Reuse auth token upon restart / recreate

[mrclemds]

Could you use --server-data-dir in the start script (/etc/s6-overlay/s6-rc.d/svc-code-tunnel/run) to allow vscode-cli to reuse the auth token after container restart / recreate

[tibynx]

I didn't use that argument, because originally I didn't want to store the server binaries in the $HOME folder so they're in /tmp. The --cli-data-dir should keep the login session and tunnel metadata. But i could add this too.