Add "chargeup" time before attacks as a weapondef.

Hi. Currently the only way (i'm aware of) to delay a shot before firing is within the animation script. This works, but, isn't simple to work with and in .bos cannot trigger arbitrary sound effects.

It would be useful to have a weapondef that can trigger a sound effect, a ceg, and create a delay before a shot can actually fire. This can be used to fine tune the balance of high alpha damage units so they are less likely to waste shots on chaff, and so that there's an option besides instantly deleting targets as soon as they're within range. It'd be another tool in the balancer's toolbox.

Start by tracing the weapondef firing path and comparing it with the animation-script and .bos approach described in the issue. Determine how a charge-up delay, sound effect, and CEG would fit together, then define tests or gameplay checks that confirm the shot waits and the effects trigger before firing.

Written by the indexing model from the issue text.