XWIKI-19922: Docker-based PDF Export doesn't work if the XWiki server runs on Windows
* We can't use the Chrome container IP to communicate (on Windows and MacOS) unless we are also inside a Docker container (on the same network)

* Fix checkstyle errors (except Class Fan out)
* Activate checkstyle
* Remove unused code and parameters

[Misc] The pipeline logic was changed to keep the last 20 builds for contrib projects. We need to override the config to make it as it was before that change
* "env.BRANCH_NAME" is not available since we're inside a closure called inside xwikiBuild, before any git checkout is done

[Misc] The pipeline logic was changed to keep the last 20 builds for contrib projects. We need to override the config to make it as it was before that change

* Small refactoring to separate the docker container management from the PDF printing, and also to put the focus on "Chrome" because Docker is just one way to have Chrome running (it's more of an implementation detail).

- Use org.xwiki.container.Container component to retrieve the current Request
  instead of Provider<XWikiContext>

* Revert it

* fix test

Currently translated at 100.0% (163 of 163 strings)

Translation: XWiki Platform/XWiki Platform - CKEditor - UI
Translate-URL: https://l10n.xwiki.org/projects/xwiki-platform/xwiki-platform-ckeditor-ui/de/

* fix tests

* Plus some code simplification to be consistent with the contrib repo in order to port patches more easily.

  * Fix the visibility of before each method

XWIKI-20020: Add a more explicit warning before a new extension is about to be installed in the macros picker
XWIKI-20019: The "recommended" extension tag should be visible too in the macros picker

  * Fix the visibility of AfterEach method: it should never be private

  * Ensure to fallback on the old mechanism when uploading an image to a
    translated page

* Use relative references in the exclusions list
* Use POST instead of GET to retrieve the tree contents
* Also exclude the Dashbord page (it's not excluded automatically because, same as with the Sandbox page, even if it belongs to an extension, the user can modify it).

XWIKI-15091: AbstractWikiReferenceExtractor fails to extract a wiki reference if the XWiki Context isn't correctly initialized (#713)

* Consider user timezone when formating the image date displayed in lightbox
* use proper case for userTimeZone and dateFormat and add escaping
* added test to verify if the timezone is indeed taken into consideration