Update api docs and remove old attribute from User entity.

The API docs incorrectly referenced a few attributes associated with users. The 'blocked' attribute has been replaced with 'state'. Also, 'dark_scheme' seems to no longer be available in the User model so it should be removed from the exposed attributes in the API User entity.

Add color scheme ID to API User entity
Merge pull request #4115 from bke-drewb/apidocs

Update api docs and remove old attribute from User entity.