Adds ability to run local commands with functional tests.
By default, commands are run locally. It is possible to set remote
host connection parameters from pytest command line, for example:
`--hosts 'fbx@IP' --ssh-identity-file '.container/ssh/id_ed25519'`
For more options, see documentation
https://testinfra.readthedocs.io/en/latest/backends.html#ssh.
Includes a fixture `host_sudo` to run commands as sudo.
Relates to
https://salsa.debian.org/freedombox-team/freedombox/-/issues/2451#note_530752.
Signed-off-by: Veiko Aasa <veiko17@disroot.org>
Reviewed-by: Sunil Mohan Adapa <sunil@medhas.org>
