* PLT-7468 Moved more errors to use error types
* PLT-7468 Moved 404 error page to use error types
* Made helper function for rendering external links on error page
* Implement POST /oauth/apps endpoint for APIv4
* Implement GET /oauth/apps endpoint for APIv4
* Implement GET /oauth/apps/{app_id} and /oauth/apps/{app_id}/info endpoints for APIv4
* Refactor API version independent oauth endpoints
* Implement DELETE /oauth/apps/{app_id} endpoint for APIv4
* Implement /oauth/apps/{app_id}/regen_secret endpoint for APIv4
* Implement GET /user/{user_id}/oauth/apps/authorized endpoint for APIv4
* Implement POST /oauth/deauthorize endpoint