Make Multimeter sample browsing UI a bit more useful
Summary: Ref T6930. Just iterating on this a bit: add some column grouping stuff so you can slice results apart and figure out where they came from.
Test Plan:
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T6930
Differential Revision: https://secure.phabricator.com/D12626