CW-335-Add-Payfura-widget-for-XMR-Buy (#857)

* add payFura widget

* Update pr_test_build.yml

* Change Buy strings

Also add Sell string to ZH, which was missing

* minor fixes

* update alert for monero.com

---------

Co-authored-by: Justin Ehrenhofer <justin.ehrenhofer@gmail.com>
Co-authored-by: Omar Hatem <omarh.ismail1@gmail.com>

tool/utils/secret_key.dart

@@ -28,8 +28,8 @@ class SecretKey {
     SecretKey('trocadorExchangeMarkup', () => ''),
     SecretKey('twitterBearerToken', () => ''),
     SecretKey('anonPayReferralCode', () => ''),
-    SecretKey('fiatApiKey', () => '')
-
+    SecretKey('fiatApiKey', () => ''),
+    SecretKey('payfuraApiKey', () => ''),
   ];
 
   final String name;