HID: uclogic: Add support for XP-PEN Artist 22R Pro

Adds support for the XP-PEN Artist 22R Pro, including stylus, tablet frame
and pen pressure.

The tablet has 20 buttons, but need to be remapped in order since the
device reports invalid keycodes. Existing tablet functionality should
not be inhibited, as BTN0-8 is still used.

New initialization functions are added since the device differs slightly
from other UGEE v2 devices.

Signed-off-by: Joshua Goins <josh@redstrate.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>