feat: implement license type management with creation and status toggling functionality

libs/api/src/lib/features/licensing/licensing.helpers.ts

@@ -411,6 +411,18 @@ const ERROR_MESSAGES: Record<string, string> = {
     'Candidates are currently waiting to pay this fee. Removing it would leave them unable to pay and unable to continue — set a different amount instead.',
   form_schema_missing_protected_paths:
     'The form for this licence type does not contain the field this setting depends on. Add the field to the form first.',
+  license_type_key_taken:
+    'A licence type with this key already exists (it may be archived). Choose a different key.',
+  license_type_key_in_use:
+    'Applications already reference this licence type, so its key can no longer be changed.',
+  invalid_form_schema:
+    'The form schema is not consistent — a condition or field reference points at something the form does not define.',
+
+  // Exam certification catalogue.
+  rank_not_found:
+    'That STCW rank is not in the ranks registry, or has been switched off. Pick a rank from the list.',
+  certification_in_use:
+    'Exam sessions or question-bank items still use this certification. Reassign or remove those first.',
 };
 
 export function extractErrorMessage(error: unknown, fallback = 'Something went wrong'): string {