R1:56e7bde68d9b

Recognize self-URI links to Diffusion files and give them special rendering behavior

Summary:
Depends on D20530. Ref T13291. When users paste links to files in Diffusion into remarkup contexts, identify them and specialize the rendering.

When the URIs are embedded with `{...}`, parse them in more detail.

This is a lead-up to a `{src ...}` rule which will use the same `View` but give users more options to customize presentation.

Test Plan: {F6463580}

Reviewers: amckinley

Reviewed By: amckinley…