------------------
Added
^^^^^
- The titles API is now `request_titles` and `async_request_titles`,
the same as the anime API.
- Added `get_main_title`.
Deprecated
^^^^^^^^^^
- `CachedTitlesGetter` and all related classes and functions are
deprecated. This logic should be implemented by the client.
Furthermore, the way it is implemented in `mir.anidb` is
unnecessarily complex.