Extensions in hard compacting flow configuration

[zaychenko-sergei]

See epic kamu-cli#582.

Implement UI extensions to allow new configuration options to trigger hard compacting flow:

• support "Keep Metadata Only" mode - in this case, settings about sizes of the blocks are irrelevant
• "Keep Metadata Only" could be recursive or not

New options should be associated with clear user texts explaining what option does and what are the consequences of running.