This patch adds the ranges_parallelism option to repair restful API.
Users can use this option to optionally specify the number of ranges to repair in parallel per repair job to a smaller number than the Scylla core calculated default max_repair_ranges_in_parallel.
Scylla manager can also use this option to provide more ranges (>N) in a single repair job but only repairing N ranges_parallelism in parallel, instead of providing N ranges in a repair job.
To make it safer, unlike the PR #4848, this patch does not allow user to exceed the max_repair_ranges_in_parallel.
Fixes#4847Closes#14886
* github.com:scylladb/scylladb:
repair: Add ranges_parallelism option
repair: Change to use coroutine in do_repair_ranges