xkbcomp: Fix keycodes bounds - Refactor to check conflicts first for the key names and then for the keycodes. This seems more useful for the user and enable further memory optimizations. - Do not allocate until we are sure to add the keycode. The bounds are only updated afterwards, so the call to `FindKeyByName` should be more efficient. - Fixed keycodes bounds not shrunk correctly when an existing keycode is overridden. - Do not prepare keyname strings for logging if we are not going to use them.