Make a test framework for improved flexibility in authorization tests

I've created various tests for authorization (both end-to-end, as in lib, as in server), but creating tests for more complicated scenarios is quite bothersome. I think I need to create some helper functions that improve developer experience and help me speed up how fast I can create these scenarios.

Some scenarios that should be tested:

• A grants B some rights. B creates Invite that grants themself rights. A retracts B's rights. B uses earlier created Invite. Opening the Invite should result in an Unauthorized error.
• A grants B some rights to resource R through some parent P. P is removed. R should not be accessible.

Ideas on better test tools / helper functions

• Helper function that creates a Store + owner + guest + resource + parent.
• Helper function for creating an Invite.

Start by reading the existing authorization tests in lib and server to understand how Store, owners, guests, resources, parents, and Invites are currently created. Define reusable helpers for those scenarios, then cover the listed revocation and removed-parent cases and verify they produce Unauthorized errors.