Add a pair of functions to translate from input events to hid codes,
mapping most of the current hid codes defined in zephyr/usb/class/hid.h.
Use a sparse table for the mapping, which takes advantage of the fact
that code 0 is reserved. Inspired by the linux equivalent hid to input
map:
https://elixir.bootlin.com/linux/latest/source/drivers/hid/hid-input.c#L27
Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
