Closes #763: AVIF support: UI

[Miraeld]

Description

Some labels get changed from mentioning WebP to Next-gen images

Fixes #763

Type of change

• Bug fix (non-breaking change which fixes an issue).

Is the solution different from the one proposed during the grooming?

No

Checklists

Generic development checklist

• My code follows the style guidelines of this project, with adapted comments and without new warnings.
• I have added unit and integration tests that prove my fix is effective or that my feature works.
• The CI passes locally with my changes (including unit tests, integration tests, linter).
• Any dependent changes have been merged and published in downstream modules.
• If applicable, I have made corresponding changes to the documentation. Provide a link to the documentation.

Test summary

• I triggered all changed lines of code at least once without new errors/warnings/notices.
• I validated all Acceptance Criteria of the related issues. (If applicable, provide proof).
• I validated all test plan the QA Review asked me to.

[jeawhanlee]

@MathieuLamiot @piotrbak Does this need QA?

[MathieuLamiot]

I don't think so

[jeawhanlee]

Thanks @MathieuLamiot
We can merge this @Miraeld

[MathieuLamiot]

@Miraeld Since this is related to a major release, I would recommend not merging into develop but a dedicated major branch. Otherwise, it would be included in the next minor version if any ; would that be OK @piotrbak ?

(cc @Tabrisrp )

[piotrbak]

@MathieuLamiot Yes, we should have a separate branch for the major.