Endpoint arguments are masked by caller arguments

[ryneeverett]

Describe the bug
If an endpoint argument is given the same name as an argument to apiron.client.call, it will not be passed through to the formatter.

To Reproduce

>>> from apiron import JsonEndpoint, Service
>>> class GitHub(Service):
    ...     domain = 'https://api.github.com'
    ...     user = JsonEndpoint(path='/users/{method}')
    ...
>>> response = GitHub.user(method='defunkt')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/apiron/src/apiron/client.py", line 238, in call
    request = _build_request_object(
  File "/apiron/src/apiron/client.py", line 112, in _build_request_object
    path = endpoint.get_formatted_path(**kwargs)
  File "/apiron/src/apiron/endpoint/endpoint.py", line 127, in get_formatted_path
    return self.path.format(**kwargs)
KeyError: 'method'

Expected behavior
The simplest improvement would be if endpoints raised an exception when such collisions occur. This way there would be a better error message at evaluation time rather than a less clear exception when the endpoint is called.

Really though, apiron should be restructured so that kwargs passed into an endpoint aren't intermingled with those passed to apiron.client.call.

Environment:

• OS: linux
• Python version 3.10.7
• apiron version 7d1d059