Clear up the permission system

[Woseseltops]

The current permission system within Signbank has 3 layers:

1. Active vs inactive. Inactive is used for accounts that didn't confirm their email or have been disabled (former colleagues).
2. Groups: determines what kind of actions you are allowed to perform.
3. Individual dataset permissions: determines which part of the data you are allowed to see.

However, there is more going on under the hood, as I recently discovered after lots of bug hunting hours:

• Groups can also have individual dataset permissions.
• There is also the global 'view_dataset' permission. When the default get_objects_for_user function is used in the code, this gives a user with this global permission access to all datasets. The get_objects_for_user function does have an accept_global_permissions flag which can be set to False, though.

Proposed changes:

• I don't think we want to use dataset permissions on groups. Perhaps we can add a tool to manage.py to detect these and automatically delete them? Or perhaps this should be a unit test?
• I think the global 'view_dataset' permission is never needed and should be removed... not 100% sure though. If we want to keep, it should be renamed to explain to non-developers in the admin what this permission really does.

[susanodd]

The view_dataset was intended to keep people from creating new signs or altering signs in a dataset. People originally have view_dataset permission only. They were meant to request change permission.

[ocrasborn]

@Woseseltops , isn't the 'view_dataset' permission what allows Dataset Managers to give people read access to their dataset at the following page? https://signbank.cls.ru.nl/datasets/manager

[susanodd]

There are some obsolete permissions for models that have since been deleted. Django doesn't delete these automatically. [Interpreter Feedback permissions still exist in the database after deleting the model, after the migrations have been run. #873.]

Regarding the Feedback, for which the user should be in group Editor, it looks like group Publisher has the same permissions. What is the distinction between Editor and Publisher?

[susanodd]

Not sure if this is relevant, for the Senses tests, the following permissions were required for the test user:

https://github.com/Signbank/Global-signbank/blob/99c055fd15ff6d6ccf8a66c6987a6a8ab6fc41bb/signbank/dictionary/tests.py#L3722-L3726

https://github.com/Signbank/Global-signbank/blob/99c055fd15ff6d6ccf8a66c6987a6a8ab6fc41bb/signbank/dictionary/tests.py#L3777

https://github.com/Signbank/Global-signbank/blob/99c055fd15ff6d6ccf8a66c6987a6a8ab6fc41bb/signbank/dictionary/tests.py#L3828

https://github.com/Signbank/Global-signbank/blob/99c055fd15ff6d6ccf8a66c6987a6a8ab6fc41bb/signbank/dictionary/tests.py#L3868