fix logstore recovery issue

[JacksonYao287]

the recovery issue is caused by the logdev metablk recovery callback rollback_super_blk_found, it will put all the log dev to m_unopened_logdev , which will be destroyed when logservice start.

in this pr :

1 change the logic about m_unopened_logdev to make sure only those log devs which are not opened before logservice#start will be destroyed.

2 change the metablk dependency , so that rollback_super_blk_found will be called after all the log dev metablk are recovered

3 add logic to make sure the logstore of a repldev is ready before it is going to join raft group. now , we use a future to open logstore, so there might be a small case that logstore is not ready when repldev is joining raft group