Rename callable_method_pointer.h to callable_mp.h and include it explicitly

This allows removing it from `class_db.h`, significantly reducing the amount of files
that include it transitively.

Also includes some include cleanup in `control.h` and `rich_text_label.h` done while
ensure they don't depend on `callable_mp`.

modules/objectdb_profiler/editor/objectdb_profiler_plugin.cpp

@@ -32,7 +32,7 @@
 
 #include "objectdb_profiler_panel.h"
 
-#include "core/object/callable_method_pointer.h"
+#include "core/object/callable_mp.h"
 
 bool ObjectDBProfilerDebuggerPlugin::has_capture(const String &p_capture) const {
 	return p_capture == "snapshot";