Add mostly automated system preparation

Created by: BranislavRistic

This PR condenses the manual steps for hardware and system setup into a bunch of scripts that can be run once at system setup and should simplify the installation on a RPi.

Major differences to the current procedure:

• Starts a dedicated X session (does not rely on a running one, i.e. runs on the RPi OS lite image)

• CAN interface settings are in /etc/network/interfaces: no need to run resetCAN.sh anymore

• Installs boot settings to /boot/firmware on newer OS versions

• Systemd units in /etc instead of /lib

  • web service relies on running tessie

• Things to be checked: consistency with rest of README