Add send-env and set-env options to ssh command

[aacebedo]

Having similar options as SetEnv and SendEnv from the ssh client can be useful.

This PR adds those options to the ssh command.

[pascalbreuninger]

Hey @aacebedo, thanks for the PR!
I'm wondering how this differs from the --workspace-env flag in devpod up, except that you can set env vars per-connection.

Do you have a specific use case in mind?

[aacebedo]

My UC is the following.
I start a container during a CI step through a common template and I don't know before being actually used in the step which variables will be used.

With this, I am able to inject directly the variable I need when I write it.
In addition having temporary variables valid for a single command seems better than having to create a new container for each command (when using ssh --command option)

[bkneis]

LGTM, both options are supported by SSH so I don't see why we shouldn't support

[aacebedo]

I fixed the comment. Will it be possible te review please?

[aacebedo]

rebased on main and test E2E tests. It is now working

[pascalbreuninger]

@aacebedo merged!