Change some units (Reaper grenade) to effects

Reaper grenade should be an effect and not a structure
Parasitc bomb (after the unit has died, the effect still lives on as a unit) should be an effect
Force field should be an effect not a unit

This can probably be achieved here

Line 835 in 9caa515

for unit in self.state.observation_raw.units:

by removing them from units and adding them to self.state.effects

Fix ravager bile effect
While we are at it, the ravager bile is removed from the API too early before the bile has landed on the destination. Units will no longer try to dodge this and will probably take damage. This might need to be stored for a couple frames, or should this be handled bot specifically?
Tactical Nuke probably has the same problem

Completed first three tasks in 034b71a

Added Nuke to task list