R1:ae32d1afb87a

Remove unused file transforms

Summary:
Ref T7707.

- Modernize the file transform endpoint a bit.
- Delete transforms which are no longer used in the product.

Test Plan:
- Used Pholio (navigation, inline thumbs).
- Uploaded images (embed thumb).
- Changed profile picture (profile thumb).

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T7707

Differential Revision: https://secure.phabricator.com/D12807