- WallabagRestController: remove the tag deletion from the API since we can't remove a tag now, we only remove reference to entries
- RuleBasedTaggerTest: remove workaround for asserting tag are equal since problem was related to mock expects (_call instead of findOneByLabel which was removed from the tag repository)
When a new tag is created but not yet persisted, it can be duplicated.
It could happen when multiple rules match the content and at least 2 of them should attach same new tag.
Fix#1528
It will slow down the whole test suite (because it'll use doctrine command).
Remove unecessary `KernelTestCase`.
Also rename `AbstractControllerTest` to `WallabagApiTestCase` for consistency.
