Python§2: Adding Source 2 list processing functions and preludes loader

[Zeesky-code]

This PR implements and tests list processing functions for Source §2, addressing issue #59.

Summary of changes:

1. Added list processing functions (e.g., pair, list, map, filter, accumulate, etc.) to the standard library for Source §2.
2. Implemented a prelude system to load Python-language implementations of complex list functions.
3. Updated context creation and stdlib loading to support chapter-based features.

[Fidget-Spinner]

I'll try to review this soon. Just got back.

[Fidget-Spinner]

Can you please check out the CI failures first? Thanks!