fix: add full DurableClientConverter class

[hallvictoria]

Python 3.14 matches durableClient binding types with the durableClientConverter instead of Generic. This caused an error when executing:

Executed 'Functions.durable_client' (Failed, Id=ba78fdb6-6243-4618-84c2-f50530945a20, Duration=195ms)
[2025-10-31T18:27:26.009Z] System.Private.CoreLib: Exception while executing function: Functions.durable_client. System.Private.CoreLib: Result: Failure
Exception: TypeError: unable to decode incoming TypedData: unsupported combination of TypedData field 'string' and expected binding type <class 'azure.functions.durable_functions.DurableClientConverter'>

This PR updates the DurableClientConverter class to fully match all of the implemented methods of Generic converters/