Feature request: (Host-specific) remote command prefix

[pbsds]

When working on various remote hosts, it would be nice to prefix the remote COMMAND with something. This could either because the remote is shared, warranting prefixing all command with nice -n 5, or because the command needs to run inside some docker container with docker run, or because it has to queued in some job system such as SLURM.

Specifically, the command here would be nice to if it could be prefixed.

One way this could be configured in .remotes.toml would be:

[general]
cmd_prefix = ["nice", "-n", "5"]

[[hosts]]
host = "..."
cmd_prefix = ["docker", "run", "-it", "MYIMAGE", "-v", "/some/folder:/some/path"]

[[hosts]]
host = "..."
cmd_prefix = ["srun", "--account=foobar", "--mem=4g", "--cpus-per-task=4"]

[[hosts]]
host = "..."
cmd_prefix = [] # no prefix, ignores the default in [general]

This way enables you to have both a default prefix, with the option to override it per remote host