Use "tag" more consistenty when referring to associating a project with an object

Summary:
Ref T10144. This isn't comprehensive, but we can give it a try and see how it feels?

• EditEngine forms now say "Tags" instead of "Projects".
• Modern SearchEngine forms now say "Tags" instead of "Projects".
• For clarity, replaced as much "in project" language as I could find with "tagged with project" language.

Test Plan: reading / grepping + used "not tagged with any project" token

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10144

Differential Revision: https://secure.phabricator.com/D15108