XWIKI-23654: Convert finder.less to CSS

[Sereza7]

Jira URL

https://jira.xwiki.org/browse/XWIKI-23654

Changes

Description

• Converted and moved the file.

Clarifications

• The comment somehow didn't get through. The inline comment syntax for LESS is not supported in CSS: https://lesscss.org/#comments adding this to the list of points to take care about when migrating at https://www.xwiki.org/xwiki/bin/view/Documentation/DevGuide/FrontendResources/Style%20variables/#HComments .
• The stylesheet code quality could definitely be improved, but it's not in the scope of this PR. I kept changes minimal to close the ticket.

Screenshots & Video

We can see on these screenshots that the updated CSS file was working as expected on my test instance:

Executed Tests

Built the changes with mvn clean install -f xwiki-platform-core/xwiki-platform-tree/xwiki-platform-tree-webjar -Pquality then used the build on my local instance (see screenshots above). The LESS compilation step is not necessary when building anymore, but the result of the build is pretty much the same as before: one finder.min.css file and one finder.css file.

When looking for uses of this file, I could only find references to finder.min.css: https://github.com/search?q=repo%3Axwiki%2Fxwiki-platform%20finder.min.css&type=code
All of still worked as expected.

Expected merging strategy

• Prefers squash: Yes
• Backport on branches:
  • None