Assertion error when attempting to use len()

[justinlietz]

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Describe the bug

cudaq.qvector supports the .size() function, but if the user mistakenly uses len() the error that is return is:
AssertionError
which is not enough to diagnose the problem.

Steps to reproduce the bug

import cudaq

@cudaq.kernel
def test_kernel(nCountingQubits: int):
    qubits = cudaq.qvector(nCountingQubits)
    # N = counting_qubits.size()
    N = len(qubits)
    h(qubits)

nQubits = 4 
print(cudaq.draw(test_kernel, nQubits))

Expected behavior

Expected behavior would be to either support len() as well as .size() or throw an error explaining that len() is not allowed.

Is this a regression? If it is, put the last known working version (or commit) here.

Not a regression

Environment

-Docker Image ID: 109eb1c12738

Suggestions

No response