The current Item categorization uses JENKINS_URL/categories endpoint to provide the list of categories.
It causes several concerns:
- Categories apply to items only, but the "/categories" endpoint does not mention it in paths. Once we want to implement slave categories, it may become a problem
- The endpoint may conflict with existing closed-source plugins. E.g. I had the Categorization plugin at one of my previous companies, which used the similar endpoint. Update to 2.0 will cause regressions in such plugins
- The implementation is not pluggable. E.g. Views and Items cannot filter the categories somehow
- Ship categories via VIEW_URL/itemCategories
- Allow overriding of the method in views. Just for the future pluggability