locale: drop Virtual-Key as intermediate format for xkbfile

locale: drop Virtual-Key as intermediate format for xkbfile

There is no 1:1 mapping between Virtual-Key codes and the "scancodes" used in
the rdp protocol. Some examples are VK_RETURN and VK_DIVIDE and US keyboards
where two different physical keys with different "scancodes" in the protocol
map to the same Virtual-Key on the server. Another bad fit seems to be the
Japanese backslash key.

The rdp scancodes are apparently undocumented and different from everything
else. The best we can do is to reverse engineer the protocol values and give
them some descriptive names and try to figure out how they relate to the native
scancodes on the supported platforms.