[lib] Add unit tests for user-facing permissions to verify the result
Summary:
A couple of unit tests that verifies the permissions from getRolePermissionBlobs for Members match the thread permissions associated with user-surfaced permissions that Members would have. For admins, this verifies that the compilation of all universalCommunityPermissions and thread permissions associated with all user-surfaced permissions matched the permissions blob.
It made the most sense to check the Members for both COMMUNITY_ROOT and COMMUNITY_ANNOUNCEMENT_ROOT, but the Admins permissions blob should remain the same so I only did that once.
Originally brought up in D8380
Depends on D8445
Test Plan: yarn workspace lib test - all tests pass
Reviewers: atul, ginsu
Reviewed By: atul, ginsu
Subscribers: ashoat, tomek
Differential Revision: https://phab.comm.dev/D8478