Provide a more modern way to load packages owning a set of files

Summary:
Ref T8320. Ref T8004. This just tries to generally modernize

It also replaces the nonfunctional "Find Owners" link with a new property that just shows owning packages.

Test Plan:

• Created and edited packages.

{F720478}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T8004, T8320

Differential Revision: https://secure.phabricator.com/D13911