Consider behavior of find_one() functions in the case of multiple matches

[tnederlof]

The find_one() function returns the first if multiple are found. It is documented in the README here:

posit-sdk-py/src/posit/connect/README.md

Line 33 in 62ff359

* If more than one entity match the query, `.find_one()` returns the first

IMO it would be safer to error out on these functions, especially with endpoints that accept a prefix parameter since users may be searching with prefix, which can easily match multiple users inadvertently (Users find_one() searches username, first name, and last name for example).

[tdstein]

This behavior matches the get method signature better than the find_one method.

Currently, the existing get methods accept a unique identifier and then raise an exception if the resource isn't found. However, this is a good reason to expand the method signature for different query patterns.

If we implement this, we should consider raising a different exception for zero results and more than one result.

[tdstein]

Relates to #294