Python: restructured the client classes, agent verbs

[eavanvalkenburg]

Motivation and Context

Added some extra ways to provide functions to the models, and allow more things to be set in the client constructor, rather then the call that get's called by the async context manager.

Description

• This also splits the backend classes into a new file called _open_ai_realtime.py keeping only the public classes available in the open_ai_realtime.py file.
• Adds additional ways of setting up
• Adds usage of model_extra to set things up in the constructor

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄

[markwallace-microsoft]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
semantic_kernel/connectors/ai
realtime_client_base.py	36	1	97%	120
semantic_kernel/connectors/ai/open_ai/services
_open_ai_realtime.py	430	139	68%	268–275, 350, 358, 402–406, 430–433, 524–525, 528–529, 532–536, 539, 547–550, 557, 559, 562–563, 613–616, 625–628, 640–641, 680, 686–694, 704–748, 754–755, 758–759, 763–793, 801–810, 814–833, 854, 857, 860–870, 873–879
azure_realtime.py	29	8	72%	90–105, 123
open_ai_realtime.py	37	6	84%	100–101, 103, 179–180, 182
semantic_kernel/services
ai_service_client_base.py	22	1	95%	64
TOTAL	19639	2572	87%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3208	5 💤	0 ❌	0 🔥	1m 34s ⏱️