Use str repr for param table html repr when __name__ does not exist

[nvaytet]

This uses the string representation for the html_repr column names in the case where .__name__ is not defined.
This is the case for python<3.10.

One slightly annoying thing is that when you have a parameter defined as Filename[Sample], in py310 the column header will be Filename, while in py39 it becomes Filename[Sample].

I could not use the string repr (with module name stripped) for all cases, because when you have a type defined simply as Filename = NewType('Filename', str), then the column name becomes something like new_type at 0x7f48681074c0>. In this case it is better to use the .__name__.
So we use the name when we can, and the string repr when .__name__ is not available.

Fixes #38

[nvaytet]

Maybe #31 is related?