terminal/idev: don't remove consumed-mods from kbd-matches

XKB consumed mods include modifiers that *didn't* affect the translation,
but might affect it if used. This is very misleading, given that we are
usually not interested in that information. Therefore, keep them in real
mods to behave like X11 does. Maybe at some point, XKB introduces proper
shortcut matching...

Also make evcat display consumed modifiers so we can better debug those
situations.