Function apply_modulator_vector 

pub fn apply_modulator_vector(
    network: &mut SpikingNetwork,
    stimuli: &[f32],
    vector: &ModulatorVector,
) -> Result<Vec<usize>, StepError>

Step a network using critic modulators converted via to_neuromodulators.

Convenience for orchestration layers that hold a ModulatorVector from SimpleCritic / TDCritic and need a single call into neuromod.