add new command to delete stale omap objects

[yati1998]

Add a new omap command to list all the stale omap objects and delete them.
Check this for more details:
#237 (comment)

[travisn]

Can you describe the scenario more? Will users commonly hit this issue, or not so common if they are following recommended practices?

[yati1998]

There can be cases where the subvolume was deleted but the omaps were not clean, which will result in having a stale omap. Currently, in the deletion of omap we are deleting the omap object and key only for the stale subvolumes to avoid these kinds of scenarios.

[travisn]

Sounds good, so we don't expect it to be common, but it may be possible.

[subhamkrai]

@yati1998 this is done right?

[yati1998]

No, it is not done, it will be different from the subvolume cleanup.