Generalize signals

[johanos1]

Issue

Problem Description

The signal.py file assumes that data can be represented as a numpy array. This is not true for all use-cases and we should generalize this to accept an index and the handler instead to fetch the data.

Expected Behavior

Ability to evaluate signals for arbitrary datasets.

What Needs to be Done

Update all the functions in signal.py to accept handler and indices.

How Can It Be Tested or Reproduced

Run attacks.