Support for Embeded chat (#9129)

* Add ucLive support

crazy testing

lovely logs

more cookie work arounds

Added Access-Control-Expose-Headers to user login

Add complete_saml_body template and revert loginWithSaml endpoint

Set Access-Control-Allow-Credentials to true in user login

Login via email instead of username

Clean up code

Add comment to give some context

Move faml logic into saml function

Communicate via chrome sendMessage api

Remove unused code

Add config to support multiple extensions

Clean up embedded complete_saml template

Fix indentation for templates

Added license header to extension.go

Add EnableExperimentalExtensions flag

Extension validated for email auth

Clean up api auth code

Remove complete_saml_body.html

* Add extension support in saml

* Clean up code

* Clean up extension validation

i18n/en.json

@@ -2166,6 +2166,22 @@
     "id": "api.user.send_deactivate_email_and_forget.failed.error",
     "translation": "Failed to send the deactivate account email successfully"
   },
+  {
+    "id": "api.user.saml.app_error",
+    "translation": "Unable to process SAML login request."
+  },
+  {
+    "id": "api.user.saml.extension_unsupported",
+    "translation": "Extensions are not supported."
+  },
+  {
+    "id": "api.user.saml.extension_id.app_error",
+    "translation": "Invalid extension id"
+  },
+  {
+    "id": "api.user.saml.invalid_extension",
+    "translation": "Extension with extension_id={{.ExtensionId}} is not supported."
+  },
   {
     "id": "api.user.send_email_change_email_and_forget.error",
     "translation": "Failed to send email change notification email successfully"