Add PyList_Extend & PyList_Clear to pyo3-ffi

[bschoenmaeckers]

Pulled the binding of PyList_Extend out of #4664 and included PyList_Clear for completeness so we can ship this in the upcoming release.

[codspeed-hq]

CodSpeed Performance Report

Merging #4667 will improve performances by 15.59%

_{Comparing bschoenmaeckers:pylist-clear-extend (ee2f4cc) with main (2d3bdc0)}

🎉 Hooray! pytest-codspeed just leveled up to 3.0.0!

A heads-up, this is a breaking change and it might affect your current performance baseline a bit. But here's the exciting part - it's packed with new, cool features and promises improved result stability 🥳!
Curious about what's new? Visit our releases page to delve into all the awesome details about this new version.

Summary

⚡ 5 improvements
✅ 78 untouched benchmarks

Benchmarks breakdown

	Benchmark	main	bschoenmaeckers:pylist-clear-extend	Change
⚡	test_empty_class_init_py	15.3 µs	13.8 µs	+10.85%
⚡	test_args_kwargs_py	21.1 µs	18.5 µs	+14.09%
⚡	test_args_kwargs_rs	15.8 µs	13.7 µs	+15.59%
⚡	test_simple_kwargs_py	22.3 µs	20 µs	+11.83%
⚡	test_simple_kwargs_rs	21.6 µs	18.8 µs	+14.55%