v4.0 better admin option pages, better taxonomy, safer and more stable

Added new automatized refresh of the cache function, a cool feature that will ensure that you cache is up to date forever! Fixed also the taxonomy system, it now creates proper links towards taxonomy pages (ie: https://yourblog.com/lumiere-director/stanley-kubrick) within widgets/into the posts sections, with the appropriate language. Taxonomy for items (ie: genre) is now displayed for all items found. Added the general advanced option to add an extra delay when querying the IMDb website. Data downloading from imdb website is retried 3 times before giving up. Fixed bug in plugin activation, layout in admin data options position, improved Content security policy and HTML 4.1, PHP 8.0, PHP 8.3 compatibility. Banning bots is now executed before doing any IMDb search or display, avoiding cache creationg (and 504 HTML errors when calling IMDb website!). Improved the comments in admin sections. Under the hood, the admin option pages have been cleaned and rewrote.

And much more! This is a major new version, more stable and safer, extensively tested before release.

!Important: Due to the improvement of the taxonomy system, it is advised to remove all "lumiere-XX" taxonomy tags that may have been automatically created. Just go to the Posts admin section, and delete all tags found under "lumiere-XX" taxonomy (ie: lumiere-director) you may have on the left menu. Tags will be created again when visiting your pages with IMDb widgets/into the posts sections. Important again: if you are a Polylang plugin user, make sure to activate in "Settings -> Custom post types and Taxonomies -> Custom taxonomies" your Lumière taxonomies

Full Changelog: https://github.com/jcvignoli/lumiere-movies/commits/4.0