Merge branch 'gtk-dyn-autocomplete'

Implement dynamic wxTextEntry autocompletion for wxGTK.

See https://github.com/wxWidgets/wxWidgets/pull/690

Closes #18061.

interface/wx/textentry.h

@@ -52,10 +52,6 @@ public:
         Call this function to enable auto-completion of the text typed in a
         single-line text control using the given @a choices.
 
-        Notice that currently this function is only implemented in wxGTK2,
-        wxMSW and wxOSX/Cocoa (for wxTextCtrl only, but not for wxComboBox)
-        ports and does nothing under the other platforms.
-
         @since 2.9.0
 
         @return
@@ -82,9 +78,6 @@ public:
         Notice that you need to include @c wx/textcompleter.h in order to
         define your class inheriting from wxTextCompleter.
 
-        Currently this method is only implemented in wxMSW and wxOSX/Cocoa (for
-        wxTextCtrl only, but not for wxComboBox).
-
         @since 2.9.2
 
         @param completer