MetaX: Add redirect user sync (prebid#4243)

Author: AntoxaAntoxic

src/main/resources/bidder-config/metax.yaml

@@ -16,3 +16,9 @@ adapters:
         - audio
       supported-vendors:
       vendor-id: 1301
+    usersync:
+      cookie-family-name: metax
+      redirect:
+        url: https://cm.metaxads.com/pixel?gdpr={{gdpr}}&gdpr_consent={{gdpr_consent}}&us_privacy={{us_privacy}}&gpp={{gpp}}&gpp_sid={{gpp_sid}}&redir={{redirect_url}}
+        support-cors: false
+        uid-macro: '[UID]'