Fix UBSAN errors in unit tests

[hallfox]

This is mostly addressing the outstanding issues in #829. There are a handful of changes:

• Deleted tests that were intentionally invoking UB by casting an out of range int to an enum
• Fixed the status code handling in queue FSM mode to appropriately convert out of range error codes into the UKNOWN category
• Fixed other test cases with UB

[678098]

=========================== short test summary info ============================
FAILED test_cluster_node_shutdown.py::TestClusterNodeShutdown::test_primary_shutdown_with_proxy[multi_node-eventual_consistency] - assert 0 == 1
 +  where 0 = len([])
======== 1 failed, 171 passed, 1 skipped, 5 rerun in 1510.55s (0:25:10) ========

I think I've seen this error in another PR, might be a problem with IT itself