Add ChatTools and ResponseTools helper classes

[christothes]

This PR adds functionality for managing OpenAI function tools in chat completions and responses, implementing two utility classes: ChatTools and ResponseTools.

Key Features

• Unified Tool Management
  • Both classes handle local and remote MCP (Model Context Protocol) tools
  • Support for both static method tools and remote MCP server tools
  • Vectorized tool lookup using embeddings for smart tool filtering
• Tool Registration
  • Local tool registration via reflection from static methods
  • Remote tool registration from MCP servers
• Tool Filtering
  • Vector-based tool filtering when an EmbeddingClient is provided
  • Configurable similarity thresholds
  • Customizable maximum tool limits

[joseharriaga]

Consider adding a test for the following scenario: I have an ongoing chat where the model called "Function Foo" at some point, but then I remove "Function Foo" from the list of available tools and continue talking to the model. Confirm that when the model sees "Function Foo" in the chat history but not in its list of available tools, it still works correctly.