Add a --workdir option to 'run'

[debarshiray]

Ptyxis currently enters a Toolbx container in a new terminal by directly using Podman's start and exec commands. We need to work out a way to make it use toolbox(1) because Toolbx's enter and run commands have become more than just those Podman commands and some recent Toolbx features might not work without going through toolbox(1).

I think the run command is more appropriate for terminal emulation applications like Ptyxis because it already supports --preserve-fds, which is something these apps need.

Ptyxis needs a way to explicitly mention the working directory when entering a Toolbx container in a new terminal to ensure that the directory is preserved. This is because the Ptyxis process that creates a new pseudoterminal and will spawn toolbox(1) against it, has a different current working directory than the one in the user's previous terminal. Therefore, toolbox(1) cannot automatically find out what the working directory should be.

One way to address this would be to mirror the --workdir option of podman exec in toolbox run.