[azure-ai-language-conversation-authoring] Codegen: allow client-scoped path param (e.g., projectName) so we don’t have to patch each operation group

In azure-ai-language-conversations-authoring, the generated operations require project_name on every call. We introduced ConversationAuthoringProjectClient and patched each operation group to capture project_name in __init__ and pass it through internally. While this works, it creates long-term maintenance overhead and duplicates logic across operation groups.

Python codegen currently doesn’t support client-scoped path parameters. In the future, I will follow up with codegen support to promote a required path parameter (e.g., projectName) to the client scope, so operation methods no longer expose it and operation groups automatically read it from the client context.