Track parent compositor dmabuf capabilities on wayland on wayland

When running as a wayland compositor connected to another wayland
compositor, we don't want to advertise dmabuf capabilities if the
parent compositor doesn't support them.

If it does, we'll want to proxy dmabuf requests to it instead of handling
them ourselves.

Expose this as new bools in e_comp_wl.

src/bin/e_comp_wl.h

@@ -251,6 +251,9 @@ struct _E_Comp_Wl_Data
    E_Drag *drag;
    E_Client *drag_client;
    void *drag_source;
+
+   Eina_Bool dmabuf_disable : 1;
+   Eina_Bool dmabuf_proxy : 1;
 };
 
 struct _E_Comp_Wl_Client_Data

src/modules/wl_wl/e_mod_main.c

@@ -23,6 +23,11 @@ _cb_sync_done(void *data EINA_UNUSED, int type EINA_UNUSED, void *event)
 
    e_comp_canvas_resize(w * 2 / 3, h * 2 / 3);
 
+   if (!ecore_wl2_display_dmabuf_get(e_comp_wl->wl.client_disp))
+     e_comp_wl->dmabuf_disable = EINA_TRUE;
+   else
+     e_comp_wl->dmabuf_proxy = EINA_TRUE;
+
    return ECORE_CALLBACK_PASS_ON;
 }