Modernize "projects" typeahead datasource

Summary: Ref T4420. Update "projects" source.

Test Plan:

• Edited projects on a Differential revision.
• Edited projects on a commit.
• Edited projects on a repository.
• Edited projects in feed search.
• Edited projects in a Herald rule field.
• Edited projects in a Herald rule action.
• Edited projects in Maniphest batch editor.
• Edited projects on Maniphest task.
• Edited projects in "Associate Projects..." action in Maniphest.
• Edited projects on Maniphest search in "all projects", "any project" and "not projects" fields.
• Edited projects on a Paste.
• Edited projects on a Pholio mock.
• Edited projects on a custom policy rule.
• Edited projects on a Ponder question.
• Edited projects on a Diffusion search query.
• Edited projects on a global search query.
• Edited projects on a slowvote.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T4420

Differential Revision: https://secure.phabricator.com/D9884