Fix TypedListConstant.signature() being unhashable and uncomparable

[Sanjays2402]

Description

TypedListConstant inherited the base Constant.signature(), which returns (self.type, self.data). For a typed list, data is a Python list of arrays, so the signature raised on both operations it exists to support:

c1.signature() == c2.signature()  # ValueError: truth value of an array with more than one element is ambiguous
hash(c1.signature())              # TypeError: unhashable type: 'list'

Since signature() backs value-based equality and hashing (merge_signature, AtomicVariable.equals, FrozenApply interning), Constant.equals() on two typed list constants raised too. It now delegates to the inner type's constant signatures and returns a plain tuple, mirroring ScalarConstant/TensorConstant.

This addresses problem 2 of #2044; the other items there (bare Constant() instantiations, constructor dispatch) are left alone.

Related Issue

• Closes #
• Related to Constant.signature() is broken or missing for several subclasses #2044

Checklist

• Checked that the pre-commit linting/style checks pass
• Included tests that prove the fix is effective or that the new feature works
• Added necessary documentation (docstrings and/or example notebooks)
• If you are a pro: each commit corresponds to a relevant logical change

Type of change

• New feature / enhancement
• Bug fix
• Documentation
• Maintenance
• Other (please specify):