WebContent: Add IPC call to set window handle from WebContent client

Author: https://github.com/kalenikaliaksandr
Commit: 6d91d2fa50
Pull-request: https://github.com/SerenityOS/serenity/pull/17855
Reviewed-by: https://github.com/linusg
Reviewed-by: https://github.com/trflynn89 ✅

Userland/Services/WebContent/WebContentServer.ipc

@@ -10,6 +10,7 @@
 endpoint WebContentServer
 {
     get_window_handle() => (String handle)
+    set_window_handle(String handle) =|
 
     connect_to_webdriver(DeprecatedString webdriver_ipc_path) =|