When uninit FileClient and some files are not closed, in
FileInstance's destructor it will destroy LeaseExecutor, but
LeaseExecutor's destructor will wait for backend lease task to stop,
so without explicit close a file, thread will be stuck here.
Signed-off-by: wuhanqing <wuhanqing@hotmail.com>

add FromHeartbeatCopySetInfoToTopologyOne leader init

This reverts commit 1d833189.

This reverts commit 4dc896bd.

After #172 and #209, source volume data of the clone volume
can be read within the client through SourceReader, and each
source volume was also opened and represented by a FileInstance,
but `FileInstance::mdsclient_` points to `FileClient::mdsClient_`,
so after FileClient is destroyed, `FileInstance::mdsclient_`
becomes dangling pointer.

To fix this problem, we let `FileClient::mdsClient_` be a shared_ptr,
and each FileInstance holds ownership of it.
Signed-off-by: Hanqing Wu <wuhanqing@corp.netease.com>