Support using `docker compose` (docker compose v2) instead of
`docker-compose` (v1)
- Introduce `COMPOSE_V2` and `COMPOSE_COMMAND` variables
- Keep the default version at v1 (`COMPOSE_V2=0`)
- Refactor error message to expose that possibility
Signed-off-by: Nicolas signed-log FORMICHELLA <stigpro@outlook.fr>