calibrate: add a `--udev` option that will yield complete udev rules

[Saviq]

Rather than going through the steps in https://mir-server.io/docs/howto-calibrate-a-touchscreen-device, it would be good if this was enough:

$ libinput.calibrate-touchscreen --udev | sudo tee /etc/udev/rules.d/touchscreen.rules

Or maybe even:

$ libinput.calibrate-touchscreen --write-udev
Starting the calibrate-touchscreen app: touch the target spots.
(Or press <ESC> to quit!)
Calibration = 1.008, 0.001, -0.002, -0.012, 1.003, 0.002

Will write udev rules to /etc/udev/rules.d/<name>.rules
[sudo] password for ubuntu: