Added button to resend 2fa code

refs [ENG-1644](https://linear.app/tryghost/issue/ENG-1644/add-re-send-ui-flow)

ghost/admin/app/controllers/signin-verify.js

@@ -30,6 +30,7 @@ class VerifyData {
 export default class SigninVerifyController extends Controller {
     @service ajax;
     @service session;
+    @service ghostPaths;
 
     @tracked flowErrors = '';
     @tracked verifyData = new VerifyData();
@@ -62,4 +63,24 @@ export default class SigninVerifyController extends Controller {
             }
         }
     }
+
+    @task
+    *resendTokenTask() {
+        const resendTokenPath = `${this.ghostPaths.apiRoot}/session/verify`;
+
+        try {
+            yield this.ajax.post(resendTokenPath, {
+                contentType: 'application/json;charset=utf-8',
+                // ember-ajax will try and parse the response as JSON if not explicitly set
+                dataType: 'text'
+            });
+            return true;
+        } catch (error) {
+            if (error && error.payload && error.payload.errors) {
+                this.flowErrors = error.payload.errors[0].message;
+            } else {
+                this.flowErrors = 'There was a problem resending the verification token.';
+            }
+        }
+    }
 }

ghost/admin/app/templates/signin-verify.hbs

@@ -41,6 +41,14 @@
                     data-test-button="verify" />
             </form>
 
+            <GhTaskButton
+                @buttonText="Resend verification code"
+                @successText="Verification code sent"
+                @task={{this.resendTokenTask}}
+                @class="login gh-btn gh-btn-login gh-btn-block gh-btn-icon"
+                @type="submit"
+                data-test-button="resend" />
+
             <p class="{{if this.flowErrors "main-error" "main-notification"}}" data-test-flow-notification>{{if this.flowErrors this.flowErrors this.flowNotification}}&nbsp;</p>
         </section>
     </div>