Phase Out hasElevatedPerms function

[AydanPirani]

Replace this with newly-added hasStaffPerms and hasAdminPerms functions. Advantages: more granularity, and it's easier for us to define custom behaviors per-roles, as opposed to having a single "catch-all" role for elevated perms.

https://github.com/HackIllinois/adonix/blob/8169ebb4b2a9b489074296c72ef19a7b8369cbad/src/services/auth/auth-lib.ts#L284C1-L284C77

[AydanPirani]

Example use case: if we have a volunteer list and add volunteers to the API, maybe volunteers have elevated access to do things like check people in - would be nice to have.