UI|Client: Game selection menu behaves differently when game loaded

Order groups differently and use different titles.
libappfw|ButtonWidget: Button text hover coloring modes

Buttons can now have a hover text color applied in two different
ways: replacing the normal color, or modulating with it.
Fixed|UI|Client: Fold title hover coloring

Fold title hover coloring (e.g., in the Renderer Appearance editor)
has been broken since ButtonWidget was changed to apply hover color
with modulation. Now fold titles are specifically requested to
use a replacement color.