Add XKB interface for x11

src/windows/ui_interfaces/x11/XcbExtensionInterface.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <unordered_map>
+#include <string>
+
+#include <xcb/xcb.h>
+
+class XcbExtensionInterface
+{
+public:
+
+    void initialize(xcb_connection_t* connection);
+
+    bool isXkBEvent(unsigned responseType) const;
+
+private:
+    bool mHasXkb{false};
+    uint8_t mXkbEventFlag{0};
+    //std::unordered_map<std::string, xcb_extension_t> mExtensions;
+};