Support origin URLs that involve paths or subfolders

[binh-dam-ibigroup]

// TODO: support root URLs that involve paths or subfolders, as in https://otp-ui.example.com/path-to-ui/

I don't think we fixed this TODO did we?

Originally posted by @miles-grant-ibigroup in #648 (comment)

This piece of code can potentially provide the functionality described in the TODO comment cited above.