stage results Table Parser fails on results with empty teams or ages

[selektormode]

The Stage Results parser fails when some rows have empty values for age or team.

In some races riders do not have a team, or PCS does not know all ages. In that case a blank value is displayed.

For example: https://www.procyclingstats.com/race/nc-germany-we/2023/result

For the age it fails because an empty string can't be cast to an int. (table_parser.py:212)
This can be fixed by not casting the age to int, but leave it as an string. I don't know if this safe

For the teams it fails because the teams are found using _filter_a_elements. But an empty cell has no a_element and thus raises an UnexpectedParsingError.

[themm1]

Sorry for being late with the fix, but it should work as expected now. The newest version isn't yet on PyPI, but it should be released soon.