refine meta backup and restore process of local storage

[linkensphere201]

this pr includes:

• meta backup and restore process of local storage refinement: fix restore failed for multiple meta service in local storage.
• add an option of backup command to show more information: now we can run with --verbose to show backup information.
• add some unit tests

[CLAassistant]

All committers have signed the CLA.

[bright-starry-sky]

One question , if SSH unencrypting fails, this command will always retry?

[linkensphere201]

One question , if SSH unencrypting fails, this command will always retry?

Good catch, it seems so. I'll check that.

[linkensphere201]

• modified as review mentioned.
• introduce a better operation to restore.
• show subcommand bugfix.
• add version infomation.

[linkensphere201]

fix #10

[linkensphere201]

• fix 2 oss backend bugs