Python implementation of ingestion, transformation and reporting

[ashbellett]

Refactor existing R implementation using Python.

[ashbellett]

Made feature/python-implementation branch for this issue. https://github.com/charliedao-eth/NterpriseFT/tree/feature/python-implementation

[ashbellett]

Current features implemented:

• Full Python package including OOP design, logging, timing, easy-to-understand API.
• Paginated API calls supporting ingestion and transformation of balances, transfers, owners, tokens and transactions.
• Dockerised, host-agnostic implementation with utility shell scripts in scripts/.
• Configuration-based inputs in data/config.json.
• Auto-documentation with sphinx in docs/.
• Progress bar for long-running request sequences with tqdm.
• Example end-to-end pipeline using World of Women NFT collection in examples/transactions.py.