feat(disk_balance): support and validate disk migration rpc

[foreverneverer]

• 1.support disk migration rpc request(RPC_REPLICA_DISK_MIGRATE) and check whether the request is valid.
• 2.add do_disk_migrate_replica to support migrate origin data feat(disk_balance): add do_disk_migrate_replica to support migrate origin data #664
• 3.close origin replica and update replica dir feat(disk_balance): close origin replica and update replica dir #668

replica migration status

   client(shell)----------->replicaServer--------->metaServer
         |                      |                     |
         |------- start ------->|----> IDLE           |
         |                      |      | (validate)   |
         |                      |     MOVING          |
         |                      |      | (copy data)  |
         |                      |     MOVED           |     
         |                      |      | (rename dir) |
         |                      |     CLOSED          |
         |                      |      |              |
         |          ------------|<- Learning <--------|
         |         |            |                     |
         |  LearningSucess      |                     |
         |         |            |                     |
         |          ----------->|                     |

as above, this pr complete the work from IDLE to MOVING