This helps users to figure if the repair has failed due to a peer node
was down during repair.
For example:
```
WARN [shard 0] repair - repair[ec2e9646-918e-4345-99ab-fa07aa1f17de]: Repair
1026 out of 1026 ranges, keyspace=ks2a, table={test_table, tb},
range=(9203128250168517738,+inf), peers={127.0.0.2}, live_peers={},
status=skipped_no_live_peers
INFO [shard 0] repair - repair[ec2e9646-918e-4345-99ab-fa07aa1f17de]: stats:
repair_reason=repair, keyspace=ks2a, tables={test_table, tb}, ranges_nr=513,
round_nr=0, round_nr_fast_path_already_synced=0,
round_nr_fast_path_same_combined_hashes=0, round_nr_slow_path=0, rpc_call_nr=0,
tx_hashes_nr=0, rx_hashes_nr=0, duration=0 seconds, tx_row_nr=0, rx_row_nr=0,
tx_row_bytes=0, rx_row_bytes=0, row_from_disk_bytes={}, row_from_disk_nr={},
row_from_disk_bytes_per_sec={} MiB/s, row_from_disk_rows_per_sec={} Rows/s,
tx_row_nr_peer={}, rx_row_nr_peer={}
WARN [shard 0] repair - repair[ec2e9646-918e-4345-99ab-fa07aa1f17de]: 1026 out
of 1026 ranges failed, keyspace=ks2a, tables={test_table, tb},
repair_reason=repair, nodes_down_during_repair={127.0.0.2}
WARN [shard 0] repair - repair[ec2e9646-918e-4345-99ab-fa07aa1f17de]:
repair_tracker run failed: std::runtime_error ({shard 0: std::runtime_error
(repair[ec2e9646-918e-4345-99ab-fa07aa1f17de]: 1026 out of 1026 ranges failed,
keyspace=ks2a, tables={test_table, tb}, repair_reason=repair,
nodes_down_during_repair={127.0.0.2})})
```
In addition, change the `status=skipped` to `status=skipped_no_live_peers`
to make it more clear.
Closes#13928
