Solves: #1555

Solution:

• rely on the mime-types library to detect the mime type from the URL and raise an error if it is not the expected type for that class
• if auto-detection of mime-type fails then we check if the file ending is among the extra extensions
  • Check for exceptional cases, if there is still no match then raise the error

CAVEAT: Any file without an extension will raise an error, for example, a wav audio file with no extension will raise an error.