FileSystemAccessServer: Add expose_window_server_client_id()

This will expose the client id of the WindowServerConnection this
instance of FileSystemAccessServer is using.

Userland/Services/FileSystemAccessServer/ClientConnection.cpp

@@ -157,4 +157,9 @@ void ClientConnection::prompt_helper(Optional<String> const& user_picked_file, C
     }
 }
 
+Messages::FileSystemAccessServer::ExposeWindowServerClientIdResponse ClientConnection::expose_window_server_client_id()
+{
+    return GUI::WindowServerConnection::the().expose_client_id();
+}
+
 }

Userland/Services/FileSystemAccessServer/ClientConnection.h

@@ -33,6 +33,8 @@ private:
     void prompt_helper(Optional<String> const&, Core::OpenMode const&);
     RefPtr<GUI::Window> create_dummy_child_window(i32, i32);
 
+    virtual Messages::FileSystemAccessServer::ExposeWindowServerClientIdResponse expose_window_server_client_id() override;
+
     HashMap<String, Core::OpenMode> m_approved_files;
 };
 

Userland/Services/FileSystemAccessServer/FileSystemAccessServer.ipc

@@ -6,4 +6,6 @@ endpoint FileSystemAccessServer
     request_file(i32 window_server_client_id, i32 window_id, String path, Core::OpenMode requested_access) =|
     prompt_open_file(i32 window_server_client_id, i32 window_id, String path_to_view, Core::OpenMode requested_access) =|
     prompt_save_file(i32 window_server_client_id, i32 window_id,String title, String ext, String path_to_view, Core::OpenMode requested_access) =|
+
+    expose_window_server_client_id() => (i32 client_id)
 }