Modify `Logic.changed` to trigger on `postTick` only after `glitch`

## Motivation
With the current implementation, if a signal is being listened to for `changed`, then it triggers an action on every `preTick` and `postTick` of the simulator. This is probably less efficient than it could be for simulator performance.

## Desired solution
It could be more efficient if listening to `preTick` was eliminated and `postTick` was only listened to after a `glitch` which caused a change.

## Alternatives considered
Leave it as-is.