Add SSO login options to desktop app (#4954)

# Description of Changes
Add SSO login options to desktop app

frontend/public/locales/en-GB/translation.json

@@ -5775,9 +5775,23 @@
       },
       "error": {
         "emptyUsername": "Please enter your username",
-        "emptyPassword": "Please enter your password"
+        "emptyPassword": "Please enter your password",
+        "oauthFailed": "OAuth login failed. Please try again."
       },
-      "submit": "Login"
+      "submit": "Login",
+      "signInWith": "Sign in with",
+      "oauthPending": "Opening browser for authentication...",
+      "orContinueWith": "Or continue with email"
+    }
+  },
+  "oauth": {
+    "success": {
+      "title": "Authentication Successful",
+      "message": "You can close this window and return to Stirling PDF."
+    },
+    "error": {
+      "title": "Authentication Failed",
+      "message": "Authentication was not successful. You can close this window and try again."
     }
   },
   "settings": {