Add option to preserve case (or not have shifted state) to .kbdgen bundle

[dylanhand]

Some keyboards such as keyboard-lut require the shift layer to have non-shifted keys.

This has been worked around specifically for lut, but this capability is also required by other languages such as crk.

This task is to:

• come up with a way of indicating that a keyboard requires this, such as a flag in the .kbdgen bundle
• implement the changes in kbdgen such that the flag added in the previous step is respected and case is preserved for that keyboard
• remove the current hard-coded workaround currently implemented in kbdgen