Invoke-DcnRepairClone: Drop broken clones

[lowlydba]

Is your feature request related to a problem? Please describe.
Add a flag/feature to allow cleanup of the metadata when clones cannot be repaired.

Describe the solution you'd like
Being able to run Invoke-DcnRepairClone -RemoveBroken and have any clones that are stuck in 'Recovery Pending' dropped and removed from the metadata.

Latest version of dbaclone as of writing
0.10.68

Additional context
I can put up a PR for this

[lowlydba]

@sanderstad Any thoughts?