fix: adds missing export

Author: iOvergaard

src/Umbraco.Web.UI.Client/src/packages/core/validation/context/index.ts

@@ -1,4 +1,5 @@
 export * from './validation.context.js';
 export * from './validation.context-token.js';
+export * from './validation-messages.manager.js';
 export * from './server-model-validator.context-token.js';
 export * from './server-model-validator.context.js';