Support for non-standard keyboard layouts in native runtime

[lambdadog]

In the native runtime if the user is using an alternative keyboard layout (at least on X11 linux), wasm4 presumably uses the character of the key rather than the keycode, which means that X and X are moved from their comfortable positions to wherever they are in the user's keyboard layout.

For dvorak, which I use, this puts X on the qwerty B and Z on the qwerty /, which isn't comfortable for play.

This does not occur in the web runtime.

[JerwuQu]

Somewhat related to #402 #366