Python: Allow hyphens in function param metadata which are sometimes present with MCP plugins

[moonbox3]

Motivation and Context

We recently relaxed the regex for FUNCTION_NAME_REGEX and FULLY_QUALIFIED_FUNCTION_NAME to allow hyphens, which are sometimes present while using MCP. However, we did not include a relaxed Regex for FUNCTION_PARAM_NAME_REGEX, which was still causing errors while using MCP within SK.

This PR relaxes the regex for FUNCTION_PARAM_NAME_REGEX so that there are no errors while using MCP.

Description

Relax the FUNCTION_PARAM_NAME_REGEX which won't throw validation errors while using MCP.

• Fully closes Bug: ChatCompletionAgent fails with Pydantic validation when MCPStdioPlugin is added for azure mcp server #11758

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
utils
validation.py	5	0	100%
TOTAL	26991	4568	83%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3616	18 💤	0 ❌	0 🔥	1m 51s ⏱️