[Python] Use Fable AST for type parameter extraction instead of Python AST heuristics

[dbrattli]

• Refactored calculateTypeParams to extract type parameters from Fable AST types directly
• Removed extractGenericParamsFromMethodSignature and its isTypeParam heuristic that guessed type params based on naming conventions
• Updated call sites in transformModuleFunction, transformAttachedProperty, and transformAttachedMethod to pass original Fable arg types

Fixes 23 type annotation errors in Python