add terminal.ssh (path to binary)

It would be very useful if the ssh binary for https://github.com/vorfol/vms-ide/blob/af1bc0dd2bd7fbf8b94cedf02079dddf0868182b/src/vms_debug/ui/terminal.ts#L71 could be configured (default `ssh` of course).

If you want to I could give that a try, ideally after #5 is solved (or just test it after the release ;-).