Recent changes allowed the Wayland driver to properly deal with numpad keys depending on numlock status. This MR ensures that numlock and other lock state is properly synced, and concludes the fix for https://bugs.winehq.org/show_bug.cgi?id=56397.
This MR also syncs the key press state when a window gains keyboard focus, including any modifier press state. Note that we currently ignore the modifier press information from the `modifier` event, since: 1. it doesn't differentiate between left-right keys, 2. mod press state changes will be normally preceded by a matching key event, so we are able to sync properly. However, if we find that we need to handle mod press state changes without corresponding key events, we will need to implement some sensible way to sync these, too.
Although I would like for the driver work exclusively in terms of scancodes, I still needed to use vkeys in this case, since this is how wineserver expresses keyboard state at the moment. This means that I had to introduce/duplicate some extra scan->vkey logic in the driver (e.g., numpad keys based on numlock state) to get things right.