Currently, in the streaming stage of rebuild tablet transition,
we stream tablet data from all replicas.
This patch series splits the streaming stage into two phases:
- repair phase, where we repair the tablet;
- streaming phase, where we stream tablet data from one replica.
rebuild_repair is a stage that will be used to perform the repair
phase. It executes the tablet repair on tablet_info::replicas.
A primary replica out of migration_streraming_info::read_from is
the repair master. If the repair succeeds, we move to streaming
tablet transition stage, and to cleanup_target - if it fails.
The repair bypasses the tablet repair scheduler and it does not update
the repair_time.
A transition to the rebuild_repair stage will be added in the following
patches.
(cherry picked from commit 4a847df55c)