In the UI, rename "Hide Inline" to "Collapse Inline"

Summary:
Ref T12733. This paves the way for a separate "hide" operation which completely hides things.

(I didn't extend this to the server side because that would require schema changes and the new "hide" state is client-only.)

Test Plan: Collapsed and expanded inlines, viewed tooltips.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12733

Differential Revision: https://secure.phabricator.com/D18126