test(qsync): add multiple tests for RAFT_PROMOTE queue

* smoke test that verifies that cluster can be successfully bootstrapped
* test diverging limbo owner (litmus test)
  - doesn't work on fork master, works with promote chains
* test aba leader
  - two cases where elected leader fails to deliver promote to others
* attempt to model 2+2 quorum lowering case
* two cases with two outstanding promotes
* use new injections for particular xrow types

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Co-authored-by: Dmitry Ivanov <ivadmi5@gmail.com>