Add the ability to setup OT&E from the web console

We create a new endpoint with a simple form that will let admins (including
support) setup OT&E for registrars.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=226570568

java/google/registry/ui/server/registrar/RegistrarConsoleModule.java

@@ -41,4 +41,16 @@ public final class RegistrarConsoleModule {
   static String provideClientId(HttpServletRequest req) {
     return extractRequiredParameter(req, PARAM_CLIENT_ID);
   }
+
+  @Provides
+  @Parameter("email")
+  static Optional<String> provideOptionalEmail(HttpServletRequest req) {
+    return extractOptionalParameter(req, "email");
+  }
+
+  @Provides
+  @Parameter("email")
+  static String provideEmail(HttpServletRequest req) {
+    return extractRequiredParameter(req, "email");
+  }
 }