Reorganized core/ directory, it was too fatty already

-Removed FuncRef, since Callable makes it obsolete
-Removed int_types.h as its obsolete in c++11+
-Changed color names code

modules/gdscript/language_server/lsp.hpp

@@ -31,8 +31,8 @@
 #ifndef GODOT_LSP_H
 #define GODOT_LSP_H
 
-#include "core/class_db.h"
-#include "core/list.h"
+#include "core/object/class_db.h"
+#include "core/templates/list.h"
 #include "editor/doc_data.h"
 
 namespace lsp {