Shell should not provide auth token in the URL query string

[CodingDoug]

Currently the shell specifies the auth token as jwt in the database URL. This can be problematic downstream. Instead, perhaps it should be using the AuthToken field of the ShellConfig struct to pass it along to libsql-shell-go so that it can be properly added in the Authorization header (which it does not currently).

https://github.com/libsql/libsql-shell-go/blob/main/pkg/shell/shell.go