Allow override.css to be used in the new back office theme

[jeckyl]

With this solution, it will be possible to customize any backoffice theme by simply adding these customization CSS elements in a file named overrides.css as it is possible to customize a PrestaShop store with the custom.css file

Questions	Answers
Branch?	develop
Description?	Allow on PrestaShop 1.7 and 8 to customize any backoffice theme.
Type?	improvement
Category?	BO
BC breaks?	no
Fixed ticket?	Fixes #30664.

[kpodemski]

Hi @jeckyl

Why not use actionAdminControllerSetMedia and add styles through the module? Don't you think it'd be easier to maintain?

[FabienPapet]

I don't have any idea about how useful this can be. Just a warning about if this get merged, it won't be available into 1.7 nor 8.0 as we don't add new features on released versions

[PrestaEdit]

Actually, the change is more: allow this overrides.css file to be used even with the new-theme.

[zuk3975]

Tested it, overriding works 👍

1. created file /themes/new-theme/css/overrides.css
2. added a test change "body { background-color: black } (see screenshot 1)
3. Without PR I don't see any changes (see screenshot 2) ❌
4. With PR I see the overriden css changes as expected (see screenshot 3) ✅

screenshots:
1.
2.
3.

[prestonBot]

QA approved, well done! Message to the maintainers: do not forget to milestone it before the merge.

[kpodemski]

Thank you @jeckyl 👏🏻