support the Cairo-like ExtTextOut for GTK3 widgetset?

[Alexey-T]

Hello,
in the last 3 weeks the developer of Lazarus made good work to fix issues in GTK3 WS. I see almost all issues with my text editor on GTK3 were fixed.
I tried to adapt Cairo's ExtTextOut for GTK3 but simple renaming of TGtkDeviceContext to TGtk3DeviceContext (and change of unit name to Gtk3Objects) did not help.
can you adapt code for GTK3, please.
In the separate unit to avoid many IfDefs.
@AlexanderBagel

[AlexanderBagel]

Maybe later