Move editing "Local Path" to modern UI/controller/etc

Summary: Fixes T1286. Ref T2231. See previous diffs; same as the others but does "Local Path".

Test Plan: See screenshots.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1286, T2231

Differential Revision: https://secure.phabricator.com/D7409