Use shared form controls and enforce UI patterns (Refs #110)

src/lib/ui/field-context.ts

@@ -1,6 +1,6 @@
 export const fieldContext = Symbol('field');
 export interface FieldContext {
-    readonly labelId: string;
+    readonly labelId: string | undefined;
     readonly messageId: string | undefined;
     readonly invalid: boolean;
 }