Move handle fetching into tokenizer Datasources

Summary:
Ref T7689. This serves two goals:

• I want to remove Controller->loadViewerHandles(). A nontrivial number of these callsites are loading handles to pass to tokenizers. Since tokenizers need to take strings eventually anyway, we can do less work by letting them take PHIDs now.
• A few changes out, I want tokenizers to accept parameterized tokens (like viewer(), members(differential), etc.), so the setValues() signature needs to change eventually anyway.

I made this work and converted a handful of callsites as an example; upcoming changes will convert more.

Test Plan:

• Viewed Almanac binding editor; used "Interface".
• Edited Almanac services; used "Projects".
• Edited Almanac devices; used "Projects".
• Searched for commits; used "Auditors"; "Commit Authors", "Repositories".
• Searched for calendar events; used "Created By"; used "Invited".

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T7689

Differential Revision: https://secure.phabricator.com/D12218