Fix compilation of wxFormBuilder-generated code using wxTE_XXX

Move definitions of wxTE_XXX flags that can be used with the controls
other than wxTextCtrl to wx/defs.h, as wxFormBuilder generates code
using them without including wx/textctrl.h, so that this code doesn't
compile.

This was already addressed in 2970f22a89 (Include <wx/textctrl.h> from
<wx/combobox.h> for compatibility., 2012-03-25) for wxComboBox, but it
also happened for wxSpinCtrl, so fix it once and for all by always
defining these styles.

This partially reverts the changes done in c57e33394c ([...] moved
wxTextCtrl-specific stuff from defs.h/event.h to textctrl.h, 2001-07-29)
as it turns out, 20 years later, that this wasn't such a great idea.

See #14132.

Closes #19225.

include/wx/combobox.h

@@ -15,10 +15,6 @@
 
 #if wxUSE_COMBOBOX
 
-// For compatibility with 2.8 include this header to allow using wxTE_XXX
-// styles with wxComboBox without explicitly including it in the user code.
-#include "wx/textctrl.h"
-
 extern WXDLLIMPEXP_DATA_CORE(const char) wxComboBoxNameStr[];
 
 // ----------------------------------------------------------------------------