Use password in URL to login similar as in jupyter notebook servers

[benjaminum]

Fixes #6733

This change allows passing the password in the URL to code-server to allow automatic login similar to the token in jupyter notebook servers.

We can use the following snippet to create the URL and launch code-server.

local password=$(openssl rand -hex 32)
echo http://$(hostname -f):8080/login?session_password=$password
PASSWORD=$password /path/to/code-server/bin/code-server --bind-addr 0.0.0.0:8080

Clicking on this link printed to the terminal by the above code will login the user to code-server without any interaction.

http://mycomputer.com:8080/login?session_password=fbf7cc58bbd90a9f172490f5c57201e03ca967efe424090c872b3218110f29fa

[code-asher]

Thank you for the PR!

I think we should do this on the backend rather than relying on automatically filling the form on the frontend.

If the password is in the query parameters, then we check it, if it matches then we set the cookie. We could also redirect to strip out the session_password query variable so it does not persist in the URL (otherwise someone could potentially read it).