Initial generic implementation

[Glyphack]

Initial implementation for generics

[codspeed-hq]

CodSpeed Performance Report

Merging #266 will not alter performance

_{Comparing generics-basic (1d87a01) with main (6d8bb9e)}

Summary

✅ 7 untouched benchmarks

🆕 1 new benchmarks

Benchmarks breakdown

	Benchmark	main	generics-basic	Change
🆕	type_checker[conformance_tests/generics_basic.py]	N/A	242.9 ms	N/A