Components should be reset when state changes are not due to execution

[kmantel]

In many cases, avoiding changing integrator state (mainly previous_value) during initialization is handled by checking for Component.is_initializing with the function body. Some cases are missed, due to changes after a Component is no longer detected as being initialized or due to deeper nesting of functions in Parameters, etc, leading to advanced integration state before any real execution has occurred. ex:

import psyneulink as pnl

obj = pnl.ObjectiveMechanism()
mech = pnl.ProcessingMechanism()

comp = pnl.Composition()
comp.add_node(mech)
comp.add_linear_processing_pathway([mech, obj])

integrator = pnl.SimpleIntegrator()
print(integrator.previous_value)
# [0]

comp.add_controller(
    pnl.OptimizationControlMechanism(
        objective_mechanism=obj,
        state_features=[mech.input_port],
        control_signals=pnl.ControlSignal(
            modulates=('intercept', mech),
            allocation_samples=[0],
            cost_options=pnl.CostFunctions.DURATION,
            duration_cost_function=integrator
        ),
    )
)

print(comp.controller.control_signals[0].function.duration_cost_fct.previous_value)
# [4.]

Components should be reset to a default state on initialization-like executions, from actual initialization or updates to default variable shape, for example. The manual checks in integrators are also not comprehensive, because there may be other kinds of integrator-like state in other types of Components.