Icu 16392 managed groups create (#2704)

* chore: 🤖 update manage-gropus tests to ues selectors

✅ Closes: https://hashicorp.atlassian.net/browse/ICU-16392

* refactor: 💡 small clean up

ui/admin/app/components/form/managed-group/ldap/index.hbs

@@ -117,7 +117,9 @@
     {{#if @model.errors.group_names}}
       <F.Error as |E|>
         {{#each @model.errors.group_names as |error|}}
-          <E.Message>{{error.message}}</E.Message>
+          <E.Message
+            data-test-error-message-group-names
+          >{{error.message}}</E.Message>
         {{/each}}
       </F.Error>
     {{/if}}

ui/admin/app/components/form/managed-group/oidc/index.hbs

@@ -67,7 +67,9 @@
     {{#if @model.errors.filter_string}}
       <F.Error as |E|>
         {{#each @model.errors.filter_string as |error|}}
-          <E.Message>{{error.message}}</E.Message>
+          <E.Message
+            data-test-error-message-filter-string
+          >{{error.message}}</E.Message>
         {{/each}}
       </F.Error>
     {{/if}}