Raft client report incomplete error cause

[sticnarf]

The old implementation doesn't wait for receiver to finish, so the errordetail will be lost. One of the example is we can see a lot of RemoteStopped send error in log with receiving error being None.

For example:

Setting server.max-grpc-send-msg-len to 10,240 and run tpcc prepare can see a lot of following logs:
[2021/09/13 21:38:51.804 +08:00] [ERROR] [raft_client.rs:407] ["connection aborted"] [addr=127.0.0.1:20161] [receiver_err=None] [sink_error=Some(RemoteStopped)] [store_id=5]

[sticnarf]

Closed by #10944