Refactor tree data structure code for better readability and maintain…

[Etzshally]

• Added type annotations to all methods for improved type safety and clarity.
• Replaced old string formatting with f-strings for better readability.
• Separated wildcard and non-wildcard logic in find_child method for clarity.
• Improved error handling with more descriptive error messages in init.
• Added docstrings to methods for better documentation.
• Handled mutable default arguments safely by using None and setting defaults within methods.
• Ensured all existing functionality remains intact.

[Etzshally]

I've reviewed, this doesn't effect the previous working of the structure.