Python: Make all AgentSkillsProvider tools require approval by default and add auto-approval rules

[SergeyMenshykh]

Summary

Port the .NET changes from #6727 to Python.

Make all functions in AgentSkillsProvider require approval by default and allow configuring auto-approval via ToolApprovalAgentOptions.

Changes to port

• Wrap all skill tools with approval required by default
• Add read-only and all-tools auto-approval rules (following the FileAccessProvider pattern)
• Remove ScriptApproval option
• Add sample showing auto-approval configuration