Bring back the schema selection.

src/Squidex/app/features/schemas/pages/schema/types/references-validation.component.html

@@ -1,4 +1,15 @@
 <div [formGroup]="editForm">
+    <div class="form-group row">
+        <label for="field-placeholder" class="col col-3 col-form-label" for="fieldSchemaId">Schema</label>
+
+        <div class="col col-6">
+            <select class="form-control" id="fieldSchemaId" formControlName="schemaId">
+                <option *ngFor="let schema of schemas" [ngValue]="schema.id">{{schema.displayName}}</option>
+            </select>
+        </div>
+    </div>
+
+            
     <div class="form-group row">
         <div class="col col-9 offset-3">
             <div class="form-check">