nodecore stateful and gate [OPTICS SPOILERS]

a central component of the [frequency halver](https://spectra.video/w/rce7KY7bNvynXq2GBZcDej). this has 3 inputs; two of them set the internal state, and the third will pass through to the output only when the internal state is in one of the two possible configurations. the frequency halver consists of one input being routed to all three of this component's inputs, in a particular order and with precise timing.