Text attributes object improvements.

* Add compare method to COLOR4D object.
* Add unit test to validate COLOR4D comparison method.
* Add missing color test in text attribute comparison method.
* Add unit test for text attribute object.
* Remove unnecessary headers from text attribute header.
* Move text attribute code into separate source file.

pcbnew/pcb_expr_functions.cpp

@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2019-2022 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2019-2023 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -24,6 +24,7 @@
 
 #include <cstdio>
 #include <memory>
+#include <wx/log.h>
 #include <board.h>
 #include <board_design_settings.h>
 #include <drc/drc_rtree.h>