"gateway" tag removed. It could be re-added if needed to overwrite the
default computed gateway for example.

JIRA INFRA-339

Tags and device_types are used as key in Ansible roles.
They shouldn't contain any spaces to avoid issues.

JIRA INFRA-334

- rename physical to physical machine
- IOC should be a tag

JIRA INFRA-302

- rename "Virtual" to "Virtual Machine"
- add "Virtual IOC"
- add several physical devices (Switch, Industrial PC IOC, MicroTCA,
  VME, PLC)

gateway tag shall be admin_only

Only keep the values really required by the application.

- We don't care about the id of the models. No need to force it.
- Rename actions