Properties on the contenttype should be also available as functions

[TG1999]

https://github.com/nexB/typecode/blob/main/src/typecode/contenttype.py#L732 for example this can be provided as a bare function which can take file as an input directly

[stefan6419846]

Would this really have any benefits over the current approach? Just creating an instance of the class with the corresponding file shouldn't be too much overhead IMHO.