[SG-656] Use a captcha bypass during registration (#3531)

* Use a captcha bypass during registration

The trial initiation flow has a registration step that automatically
does a login in the background. This has Captcha problems, namely that
it can spawn two captchas in a row - one during registration and one
during login. This is not ideal UX, so we've added a bypass token that
returns from the registration endpoint that can be used to skip the next
captcha.

* [review] Introduce ICaptcheProtectedResponse

libs/common/src/models/response/authentication/ICaptchaProtectedResponse.ts

@@ -0,0 +1,3 @@
+export interface ICaptchaProtectedResponse {
+  captchaBypassToken: string;
+}

libs/common/src/models/response/authentication/registerResponse.ts

@@ -0,0 +1,12 @@
+import { BaseResponse } from "../baseResponse";
+
+import { ICaptchaProtectedResponse } from "./ICaptchaProtectedResponse";
+
+export class RegisterResponse extends BaseResponse implements ICaptchaProtectedResponse {
+  captchaBypassToken: string;
+
+  constructor(response: any) {
+    super(response);
+    this.captchaBypassToken = this.getResponseProperty("CaptchaBypassToken");
+  }
+}