tokens have scopes
instead of roles, which allow tokens to change permissions over time
This is mostly a low-level change,
with little outward-facing effects.
- on upgrade, evaluate all token role assignments to their current scopes,
and store those scopes on the tokens
- assigning roles to tokens still works, but scopes are evaluated and validated immediately,
rather than lazily stored as roles
- no longer need to check for role permission changes on startup, because token permissions aren't affected
- move a few scope utilities from roles to scopes
- oauth allows specifying scopes, not just roles.
But these are still at the level specified in roles,
not fully-resolved scopes.
- more granular APIs for working with scopes and roles
Still to do later:
- expose scopes config for Spawner/service
- compute 'full' intersection of requested scopes, rather than on the 'raw' scope list in roles
since it means 'inheriting' the owner's permissions
'all' prompted the question 'all of what, exactly?'
Additionally, fix some NameErrors that should have been KeyErrors
