Display the link of oauth when xdg-open is not found

[ghost]

Feature description

Display the link of oauth when xdg-open is not found. Many remote linux sever does not have any browser or desktop environment. display the link would allow user to ssh bind the port and then authenticate with his laptop that connect to remote linux sever that holds the git repo.

also see https://github.com/git-ecosystem/git-credential-manager/issues/1514#issuecomment-1919106721 https://github.com/git-ecosystem/git-credential-manager/issues/1005#issuecomment-1361115725 https://github.com/git-ecosystem/git-credential-manager/issues/1490