chore: suggest url if 401

[Coniferish]

Final PR for closing #30

This PR adds a decorator to the partition method of the General class to catch if a 401 error is being raised while server_url is None and add a warning message.

Testing

from unstructured_client.models import shared
from unstructured_client import UnstructuredClient

FAKE_KEY = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"

client = UnstructuredClient(
    api_key_auth=FAKE_KEY,
)
        
filename = "_sample_docs/layout-parser-paper-fast.pdf"
        
with open(filename, "rb") as f:
   files=shared.Files(
        content=f.read(),
        file_name=filename,
   )

req = shared.PartitionParameters(
    files=files,
)

client.general.partition(req)

[scanny]

A few remarks. Code looks fine to me.

[scanny]

LGTM other than a couple formatting issues I marked. Approving in advance.