[red-knot] Cleanup some KnownClass APIs

[AlexWaygood]

Summary

• Rename KnownClass::to_class to KnownClass::to_class_literal. This is an oversight that should have been done as part of [red-knot] Introduce a new ClassLiteralType struct #14108.
• Rename KnownClass::maybe_from_moduletoKnownClass::try_from_module`. I think this fits better with typical Rust naming conventions.
• Inline KnownClass::from_name. I don't think it would ever produce desirable results if you called this method from outside of KnownClass::try_from_module (because you also need to check which module the class is coming from, for correctness), so inlining it seems best here.
• Make use of the CoreStdlibModule enum in red_knot_python_semantic/src/stdlib.rs to reduce code duplication and reduce hardcoded strings.

Test Plan

cargo test -p red_knot_python_semantic

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.