Convert Form Components to TypeScript

Co-authored-by: Mark McDowall <mark@mcdowall.ca>

Remove defaultProps from TypeScript components

(cherry picked from commit a90c13e86f798841cb6db038bb6b6d1408a00585)

Fix multi-select checkboxes not appearing

(cherry picked from commit e199710c15fbfa643a9f71c7a20f70b1722d0df6)

frontend/src/App/State/OAuthAppState.ts

@@ -0,0 +1,9 @@
+import { Error } from './AppSectionState';
+
+interface OAuthAppState {
+  authorizing: boolean;
+  result: Record<string, unknown> | null;
+  error: Error;
+}
+
+export default OAuthAppState;