[ResponseOps][Connectors] add additional function tests for pre/post save/delete hooks

[pmuellr]

In PR add pre-create, pre-update, and post-delete hooks for connectors #194081, we added jests that test for hook failures and saved object operation failures. But we only have "happy path" function tests for these cases. We should add some function tests for these, similar to the jest ones - test for hooks throwing errors and for the SO operations to fail.

Not sure if we can force an SO operation to fail in this case, from FTR - if not, we certainly can in a jest integration test, and it would be fine to add the tests that way ...

[elasticmachine]

Pinging @elastic/response-ops (Team:ResponseOps)