Task/unit tests investment and client
* move io_utils.py
* add __init__.py
* refactor: move string_funcs and update import paths to use utils namespace
* rename string_funcs to string_utils
* move and rename table_utils.py
* refactor: rename claude_funcs to llm_utils in multiple files
* update unit tests
* added unit tests for src/string_utils.py
* added unit tests for src/table_utils.py
* added unit tests for src/llm_utils.py
* added unit tests for src/io_utils.py
* Merge branch 'main' into task/unit-tests-investment-and-client; TODO: fix unit tests
* Unit tests to fix
* fix unit tests
* fix invalid references
Approved-by: Alex Galarce
Siddhant Medar