[lib] Remove threadFrozenDueToBlock, threadOrParentThreadHasAdminRole and memberHadAdminPowers
Summary:
Last usage was removed in D12543, also removed functions where only usage was via threadFrozenDueToBlock
Depends on D12543
Test Plan: flow + searching codebase to make sure there are no remaining references.
Reviewers: ashoat
Reviewed By: ashoat
Differential Revision: https://phab.comm.dev/D12554