The BaseTemplateToolbox hook adds logic to the rendering layer.
It's used in a few places:
https://codesearch.wmflabs.org/search/?q=BaseTemplateToolbox&i=nope&files=&repos=
With T252917 and @Ammarpad modification the SidebarBeforeOutput hook will be usable instead.
Let's deprecate the hook and move usages to SidebarBeforeOutput.
Acceptance criteria
- All extensions in subtasks should use SidebarBeforeOutput (Vector) instead of the BaseTemplateToolbox. This should retain support with Modern, Monobook and Cologne Blue.
- Vector should not call BaseTemplate::getToolbox
- Soft deprecate BaseTemplate::getToolbox in core
- Mark BaseTemplateToolbox hook as deprecated.