Projects - tokenize [ProjectX] so "projectX" is a match

Summary:
Fixes T4656. Helps users with this naming convention, which is probably not super duper rare.

Users will need to make an edit to a project -or- run bin/search index "#project-tag" to make this actually work.

Test Plan: made a project "[T4656test]". Typed "t4" and project showed up!

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T4656

Differential Revision: https://secure.phabricator.com/D11302