make the config file location configurable

[jacalata]

Also maybe make the location configurable where tableau_auth.json is stored. Apart from the fact that it should be in ~/.cache or maybe ~/.local/state on linux according to the XDG Base Directory Specification it should definitely not be world readable as it apparently contains the raw token!

Originally posted by @septatrix in https://github.com/tableau/tabcmd/issues/168#issuecomment-1239702516