Add UserNamePipe (#429)

angular/src/pipes/user-name.pipe.ts

@@ -0,0 +1,22 @@
+import {
+    Pipe,
+    PipeTransform,
+} from '@angular/core';
+
+interface User {
+    name?: string;
+    email: string;
+}
+
+@Pipe({
+    name: 'userName',
+})
+export class UserNamePipe implements PipeTransform {
+    transform(user?: User): string {
+        if (user == null) {
+            return null;
+        }
+
+        return user.name == null || user.name.trim() === '' ? user.email : user.name;
+    }
+}