Add a new test that verifies that when replaying batch mutations from
the batchlog, the mutations include cdc augmentation if needed.
This is done in order to verify that it works currently as expected and
doesn't break in the future.
Add a test of the batchlog manager replay loop applying failed batches
while some replica is down.
The test reproduces an issue where the batchlog manager tries to replay
a failed batch, doesn't get a response from some replica, and becomes
stuck.
It verifies that the batchlog manager can eventually recover from this
situation and continue applying failed batches.