Generate bundle code for wxRibbon classes

[KeyWorksRW]

Description:

wxWidgets 3.1.6 does still uses wxBitmap for all of the wxRibbon classes. If the user is only using a single bitmap file, this won't matter. However, if they want to switch to an SVG file, or a bundle of images, then our current code generation won't support it. This a blocking problem for wxUiEditor itself because we can't switch to SVG files for the navigation panel unless with either duplicate all the PNG files, or we handle converting the bundles to bitmaps for wxRibbon classes.

Generating usable code should be fairly straightforward -- we already do something similar for wxDialog where we convert a bundle into a bitmap, and use that to load it into an icon. In that case, we use the window of the dialog to determine which bitmap (or SVG size) to pull out of the bundle.