R1:a837c3d73eaf

Make temporary token storage/schema more flexible

Summary:
Ref T10603. This makes minor updates to temporary tokens:

- Rename `objectPHID` (which is sometimes used to store some other kind of identifier instead of a PHID) to `tokenResource` (i.e., which resource does this token permit access to?).
- Add a `userPHID` column. For LFS tokens and some other types of tokens, I want to bind the token to both a resource (like a repository) and a user.
- Add a `properties` column. This makes tokens more…