PMR: Create or Delete RoleBindings in create_or_update_profiles()

[kimwnasptd]

Resolves #11

This PR extends the create_or_update_profiles(pmr) function to:

1. create RoleBindings, for Contributors in the PMR if their RB doesn't exist
2. delete RoleBindings that don't match the Contributors in the PMR

Changes

• Updated has_kfam_annotations() to also ensure that the values of role annotation are correct (either admin, edit or view)
• Added a get_annotations() helper, to reduce a bit the pain of checking constantly for None in metadata
• Added a private attribute in the Profile class, in order to have a dict for contributors with username as a key. This would help to significantly reduce the checks needed when checking if a user with a role is a Contributor defined in the Profile
• Refactored integration tests to use a common apply_profile_and_resources() function, to avoid repetition
• Function for handling the creation / deletion of RoleBindings in a Profile

Review Notes

1. Suggested review order: create_or_update.py and then the helper functions
2. A user in the cluster could be defined with multiple roles (i.e. a RoleBinding giving them view access and another one for admin).
   4. In general, edit is a superset of view and admin a superset of edit
   5. still the code should be able to keep this in mind when cleaning up RoleBindings
3. Can't update roleRef in RoleBindings since the field is immutable, thus the need for deleting and not updating RoleBindings

Lastly, I pondered a lot on the functions and whether we should have RoleBinding specific functions or generalise them. In the end, I went with separate ones as AuthorizationPolicies will need slightly different handling (PTAL in #31)

[DnPlas]

Thanks @kimwnasptd ! A couple comments.

[kimwnasptd]

Thanks for the review @DnPlas! I went over all the comments.

A small summary of open discussions:

1. Exception handling on delete_many, let me know what you had in mind in your comment
2. Exception handling on client.apply, let me know what you had in mind in your comment
3. I would not rename has_valid_kfam_annotations to get_valid_kfam_annotations, but let me know in the comment if you feel strongly about this
4. Didn't raise an exception, when parsing empty profile contributors

[DnPlas]

Thanks, @kimwnasptd !

[mvlassis]

Great work!