Python: Improve error messages for argument type mismatch

[thomastrapp]

For example, using Python 3.12, Hext 1.0.8:

import hext
rule = hext.Rule("<a href:link/>")
# Error, the argument for extract is of type string:
results = rule.extract("""<a href="b"></a>""")

Produces an unhelpful error message:

Traceback (most recent call last):
  File "/home/dev/issue-27/issue28-example.py", line 4, in <module>
    results = rule.extract("""<a href="b"></a>""")
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/dev/issue-27/venv/lib/python3.12/site-packages/hext/__init__.py", line 139, in extract
    return _hext.Rule_extract(self, html, max_searches)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: Wrong number or type of arguments for overloaded function 'Rule_extract'.
  Possible C/C++ prototypes are:
    Rule::extract(Html const &,std::uint64_t) const
    Rule::extract(Html const &) const

The error message should explicitly state that the wrong type of argument was passed, and that an hext.Html was expected.