Add ARM support to SDO simulate-mfg.sh

[bmpotter]

So ARM devices like a raspberry pi can be "SDO-enables".

• [ ] Modify sample-mfg/Makefile to build the manufacturer and manufacturer-mariadb docker images for arm
• [ ] Modify simulate-mfg.sh to pull the above images when on arm
• [ ] Install the dnsutils debian package if the nslookup command doesn't exist
• [ ] If docker needs installing, first Install software-properties-common (needed for the add-apt-repository command)
• [x] Steal these functions from agent-install.sh: detect_distro, get_arch, get_image_arch
• [ ] Set distro and arch correctly when installing docker and docker-compose. (See agent-install.sh for an example for docker, and see https://docs.docker.com/compose/install/