feat: Introduce new tools and refactor existing ones

[notlikejuice]

• Added `FileChangePlanTool' to manage file change plans with user approval.
• Introduced `RejectFileChangesTool' to handle rejection of file changes with reasons.
• Implemented `WebSearchTool' to perform web searches and return results.
• Created `WriteToFileTool' for writing content to files with user confirmation.
• Added ReadFileTool for reading file contents with structured responses.
• Refactored existing tools to use a single `Definitions' module for parameter schemes.
• Extended ToolExecutor to include new tools and manage their execution.
• Developed utilities to generate prompts and documentation for tools.
• Updated ToolParser to support both standard and legacy XML formats for tool calls.
• Improved error handling and user feedback mechanisms for all tools.