CCM-13415: Remove enum

Author: chris-elliott-nhsd

frontend/src/utils/error-codes.ts

@@ -1,3 +1,3 @@
-export enum ErrorCodes {
-  MESSAGE_CONTAINS_INVALID_PERSONALISATION_FIELD_NAME = 'MESSAGE_CONTAINS_INVALID_PERSONALISATION_FIELD_NAME',
-}
+export const ErrorCodes = {
+  MESSAGE_CONTAINS_INVALID_PERSONALISATION_FIELD_NAME: 'MESSAGE_CONTAINS_INVALID_PERSONALISATION_FIELD_NAME',
+} as const;