Add Python data types to the data_handling module

[dragonejt]

Changes

• Add Python data types to each function definition in the data_handling module
• Working towards #109
• Used Instagram/MonkeyType to run driver.py and get some working function definitions with types, and tried to fill in the rest based off of what was returned by those functions. Please make sure that the function parameter and return types are actually correct
• Decided to stick with first-level types e.g. list instead of list[float] as some types are deeply nested, complicated multilevel types
• Added .vscode/ (VSCode configurations folder) to .gitignore

Testing

• python driver.py -t succeeded
• python driver.py did not return any errors

[the-other-james]

Hi @dragonejt, thanks for putting in this PR. I will take a look at this soon (currently pushing for a critical deadline). I agree that adding data types can help folks understand the code faster and I want to learn more about how they work in Python.

Thanks!