* [ai] Add integration test for triggering inconsistent resharding state
* [ai] Also add test for resharding down
* Update test
* Resolve resharding idempotency through setting replica states
* Remove resharding down test
* Reformat
* [ai] Remove resharding abort order, abort before setting replica state
* [ai] Resolve test flakiness
* Collapse matches into helper function
* Check preconditions before aborting resharding
* Fix test flakiness by not waiting for a dead node
* Abort resharding before aborting transfer for idempotency
* Update comment
* Release shard holder lock on transfer/reshard abort to prevent deadlock
* Remove now unused shard holder parameter
* Split handle_replica_changes to eliminate need for juggling locking
* In resharding tests, import all utils to enable every_test cleanup
Resolves flakiness I've been seeing in
test_set_replica_dead_clears_resharding_state test
ca1971ad4f