Add filter for apps for which ownership can be overriden

[100mik]

What this PR does / why we need it:

Introduces a flag which allows users to specify flags which apps ownership can be snatched from while allowing ownership overrides.

Which issue(s) this PR fixes:

Fixes #993

Introduce flag to filter out apps which we can steal ownership from while deploying

Additional Notes for your reviewer:

The only catch today, is that it is a best effort listing of apps, limited to the namespace the new app itself is being deployed in. This is in line with encouraged kapp-controller patterns.

Review Checklist:

• Follows the developer guidelines
• Relevant tests are added or updated
• Relevant docs in this repo added or updated
• Relevant carvel.dev docs added or updated in a separate PR and there's
  a link to that PR
• Code is at least as readable and maintainable as it was before this
  change

Additional documentation e.g., Proposal, usage docs, etc.:

[praveenrewar]

LGTM!
I am just trying to think if we can have a better name for the flag, otherwise looks good.

[100mik]

Some options I had thought of, ownership-override-allowed-apps, overridable-apps (not a fan), ownership-override-filter
What do you think of these? I quite like the first one, since it is technically not a filter. Filters have mainly been for user supplied resources.

[100mik]

From a convo offline, we are going with ownership-override-allowed-apps 🙌🏼

[100mik]

Created #997 and #998 to track discussions that happened while we were working on this