Closes #875 Add new option to select next-gen format

[Tabrisrp]

Description

Add a new UI setting option to select the next-gen format to generate, or disable it.

Fixes #875

• Enhancement (non-breaking change which improves an existing functionality).

Checklists

Feature validation

• I validated all the Acceptance Criteria. If possible, provide sreenshots or videos.
• I triggered all changed lines of code at least once without new errors/warnings/notices.

Code style

• I wrote self-explanatory code about what it does.
• I wrote comments to explain why it does it.
• I named variables and functions explicitely.
• I protected entry points against unexpected inputs.
• I did not introduce unecessary complexity.

Observability

• I handled errors when needed.
•  I wrote user-facing messages that are understandable and provide actionable feedbacks.
• I prepared ways to observe the implemented system (logs, data, etc.).

[Khadreal]

LGTM.

• Won't it be nice to have off as a constant considering how often it's use and its subsequent use, and if the value change or need to be modify it can be done from one point.
  Also, for UI related PR, would it be an overkill to add a screenshot of it

[Mai-Saad]

@Tabrisrp Thanks for the PR, please find exploratory test notes below (WIP)

• Next-gen options shall match that on Epic i.e NONE then WEBP then AVIF => seems Notion wasn't updated and ok as is

• Warning after uploading images with a fresh install of Imagify and optimization, it keeps loading
  1- fresh install and activate of Imagify
  2- upload image => see the warning
  
  

• Fatal error when uploading image/ optimize image while filter is used
  1- fresh install/activation of Imagify
  2- Enable the Next-Gen filter

add_filter('imagify_nextgen_images_formats', function($formats){
    $formats['webp'] = 'webp';

    return $formats ;
});

3- upload an image or click optimize for a previously uploaded image

[18-Apr-2024 07:27:09 UTC] PHP Fatal error:  Uncaught TypeError: Imagify\Optimization\Process\AbstractProcess::get_suffix_from_format(): Argument #1 ($format) must be of type string, null given, called in /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify-plugin/classes/Optimization/Process/AbstractProcess.php on line 1554 and defined in /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify-plugin/classes/Optimization/Process/AbstractProcess.php:1570
Stack trace:
#0 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify-plugin/classes/Optimization/Process/AbstractProcess.php(1554): Imagify\Optimization\Process\AbstractProcess->get_suffix_from_format()
#1 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify-plugin/classes/Optimization/Process/AbstractProcess.php(500): Imagify\Optimization\Process\AbstractProcess->is_size_next_gen()
#2 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify-plugin/classes/Job/MediaOptimization.php(181): Imagify\Optimization\Process\AbstractProcess->optimize_size()
#3 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify-plugin/classes/Job/MediaOptimization.php(66): Imagify\Job\MediaOptimization->task_optimize()
#4 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify-plugin/inc/classes/Dependencies/deliciousbrains/wp-background-processing/classes/wp-background-process.php(516): Imagify\Job\MediaOptimization->task()
#5 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify-plugin/inc/classes/Dependencies/deliciousbrains/wp-background-processing/classes/wp-background-process.php(333): Imagify_WP_Background_Process->handle()
#6 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/class-wp-hook.php(324): Imagify_WP_Background_Process->maybe_handle()
#7 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#8 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/plugin.php(517): WP_Hook->do_action()
#9 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-admin/admin-ajax.php(192): do_action()
#10 {main}
  thrown in /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify-plugin/classes/Optimization/Process/AbstractProcess.php on line 1570

• Grey out the options while the filter is enabled needs improvement (lighter in color, Read me is a link) => details here https://wp-media.slack.com/archives/CUKB44GNN/p1713425370986549?thread_ts=1713374092.801659&cid=CUKB44GNN
• Error after update from 2.2.1 while avif is enabled
  1- install and activate 2.2.1
  2- Enable avif
  3- upload a couple of images => next-gen is added
  4- update to 2.2.2 and open Imagify settings

[18-Apr-2024 08:20:03 UTC] PHP Deprecated:  strpos(): Passing null to parameter #2 ($needle) of type string is deprecated in /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify/classes/Bulk/WP.php on line 194
[18-Apr-2024 08:20:03 UTC] PHP Deprecated:  strtoupper(): Passing null to parameter #1 ($string) of type string is deprecated in /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify/classes/Bulk/WP.php on line 208
[18-Apr-2024 08:20:03 UTC] PHP Fatal error:  Uncaught Error: Undefined constant Imagify\Optimization\Process\WP::_SUFFIX in /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify/classes/Bulk/WP.php:208
Stack trace:
#0 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify/classes/Bulk/WP.php(208): constant()
#1 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify/classes/Bulk/Bulk.php(237): Imagify\Bulk\WP->get_optimized_media_ids_without_format()
#2 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify/classes/Bulk/Bulk.php(606): Imagify\Bulk\Bulk->run_generate_nextgen()
#3 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/class-wp-hook.php(326): Imagify\Bulk\Bulk->maybe_generate_missing_nextgen()
#4 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#5 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/plugin.php(517): WP_Hook->do_action()
#6 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/option.php(889): do_action()
#7 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify/inc/classes/class-imagify-abstract-options.php(372): update_option()
#8 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify/inc/classes/class-imagify-abstract-options.php(231): Imagify_Abstract_Options->set_raw()
#9 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify/inc/admin/upgrader.php(318): Imagify_Abstract_Options->set()
#10 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/class-wp-hook.php(324): _imagify_new_upgrade()
#11 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#12 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/plugin.php(517): WP_Hook->do_action()
#13 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify/inc/admin/upgrader.php(69): do_action()
#14 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/class-wp-hook.php(324): _imagify_upgrader()
#15 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#16 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-includes/plugin.php(517): WP_Hook->do_action()
#17 /var/www/mai.rocketlabsqa.ovh/htdocs/wp-admin/admin-ajax.php(45): do_action()
#18 {main}
  thrown in /var/www/mai.rocketlabsqa.ovh/htdocs/wp-content/plugins/imagify/classes/Bulk/WP.php on line 208

Note: the same fatal error occurred if we enabled avif and save settings after a fresh install of 2.2.2

[Mai-Saad]

We are good here, if UI modification with filter + read more link will be on other GH then we can merge this.
testrail-report-594.pdf