Enhance readFileTool with improved error handling and validation

- Introduced a FileEntry interface for better type management.
- Added validation for start_line and end_line to ensure proper ranges.
- Implemented RooIgnore validation before processing files.
- Enhanced error handling with dedicated functions for file and global errors.
- Streamlined file reading logic to handle binary files, definitions-only mode, and line thresholds more effectively.
- Improved user feedback for empty files and read limits.

Author: samhvw8