backend: X11 后端添加获取窗口 metadata 信息方式

src/backend/x11/internal.h

@@ -1,12 +1,23 @@
 #pragma once
 
 #include <xcb/xcb.h>
+#include <xcb/xproto.h>
 
 #include "core/backend.h" /* IWYU pragma: keep */
 
+typedef struct atoms_t {
+  xcb_atom_t COMPOUND_TEXT;
+  xcb_atom_t UTF8_STRING;
+  xcb_atom_t WM_WINDOW_ROLE;
+  xcb_atom_t WM_NAME;
+  xcb_atom_t _NET_WM_NAME;
+} atoms_t;
+
 struct backend_t {
   xcb_connection_t *conn;
   xcb_screen_t *screen;
   int screenp;
   bool have_xfixes;
+
+  atoms_t atoms;
 };