Python: prompt template config and kernel args support for agents

[moonbox3]

Motivation and Context

To bring the SK Python framework closer to .Net parity, we need to support the ability to specify a prompt template config and kernel arguments for ChatCompletion Agents as well as for Assistant Agents.

Description

This PR adds support for:

• being able to specify a prompt template config for SK agents.
• allows kernel arguments to be passed to the agent as well as during invoke - invoke args, similar to other kwargs, take precedence over agent level config.
• adds test coverage
• creates agent templating samples for both ChatCompletionAgents and OpenAI/AzureAssistantAgents
• closes Python Agents: Allow Kernel and KernelArguments override when invoking ChatCompletionAgent and OpenAIAssistantAgent` #8022
• closes Python Agents - Support PromptTemplateConfig by any agent #8699

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/agents/chat_completion
chat_completion_agent.py	110	8	93%	85, 87, 90, 99–104, 129, 193
semantic_kernel/agents/open_ai
azure_assistant_agent.py	110	4	96%	157, 159, 285, 302
open_ai_assistant_agent.py	111	5	95%	152, 154, 268, 288, 307
open_ai_assistant_base.py	524	15	97%	188, 197–202, 282, 298–299, 373–374, 770, 824, 1030, 1038, 1123, 1187
TOTAL	17056	1834	89%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3033	4 💤	0 ❌	0 🔥	1m 22s ⏱️