Add more granular OAuth scopes (#7929)

* Add more granular OAuth scopes

* Add human-readable descriptions of the new scopes

* Ensure new scopes look good on the app UI

* Add tests

* Group scopes in screen and color-code dangerous ones

* Fix wrong extra scope

spec/controllers/api/v1/media_controller_spec.rb

@@ -4,7 +4,7 @@ RSpec.describe Api::V1::MediaController, type: :controller do
   render_views
 
   let(:user)  { Fabricate(:user, account: Fabricate(:account, username: 'alice')) }
-  let(:token) { Fabricate(:accessible_access_token, resource_owner_id: user.id, scopes: 'write') }
+  let(:token) { Fabricate(:accessible_access_token, resource_owner_id: user.id, scopes: 'write:media') }
 
   before do
     allow(controller).to receive(:doorkeeper_token) { token }