Spike - RBAC AuthZ - xblock endpoint: identify use cases and match with permissions

[rodmgwgu]

Identify use cases that are covered by the xblock endpoint in edx-platorm and figure out what permissions should apply for the different use cases for the AuthZ for Course authoring project.

References:

Discovery findings on endpoints used for the different use cases on Course Authoring: https://openedx.atlassian.net/wiki/spaces/OEPM/pages/5404590081/Technical+Discovery+Notes+-+AuthZ+for+Course+Authoring#On-adding-permissions-to-existing-course-features-on-top-of-existing-API-endpoints

Proposed permissions list: https://openedx.atlassian.net/wiki/spaces/OEPM/pages/5528715266/openedx-authz+permission+list