R1:039809749869

Allow ApplicationEditor forms to be reconfigured

Summary:
Ref T9132. This diff doesn't do anything interesting, it just lays the groundwork for more interesting future diffs.

Broadly, the idea here is to let you create multiple views of each edit form. For example, we might create several different "Create Task" forms, like:

- "New Bug Report"
- "New Feature Request"

These would be views of the "Create Task" form, but with various adjustments:

- A form might have additional instructions ("how to…