fc560d4bc2
Refactor GL rendering to prepare for GTK4 - Remove FlGLArea - we can just use GtkGLArea directly - Stop using gdk_cairo_draw_from_gl, it's not available in GTK4. - Rename FlRendererGL to FlRendererGdk, this was implying that FlRenderer could be something other than OpenGL which is not the case currently. - Remove unnecessary virtual methods in FlRenderer, just implement them as standard methods. Related: https://github.com/flutter/flutter/issues/143408