Remove "DifferentialInlineCommentQuery"

Summary: Ref T13513. Replaces "DifferentialInlineCommentQuery" with the similar but more modern "DifferentialDiffInlineCommentQuery".

Test Plan: Viewed comments in timeline, changesets. Created, edited, and submitted comments. Hid and un-hid comments, reloading (saw state preserved).

Maniphest Tasks: T13513

Differential Revision: https://secure.phabricator.com/D21233