R1:34c890b7e1a8

Use modern UI and policies in OAuth client editing

Summary:
Updates this stuff a bit:

- Add a global create permission for OAuth applications. The primary goal is to reduce attack surface area by making it more difficult for an adversary to do anything which requires that they create and configure an OAuth application/client. Normal users shouldn't generally need to create applications, OAuth is complex, and doing things with user accounts is inherently somewhat administrative.
- Use normal policies…