Biter nest targeting for the upgrade/decon planner

[bobucles]

Tagging a biter nest with a capture rocket changes some kind of hidden variable so that units will no longer target them. Removing a nest is challenging, because no natural action will remove them.

"Simple" solution? Add the autotarget property as part of the upgrade planner. The capture rocket can keep its useful behavior, but the upgrade planner gains the ability to mark "shoot or do not shoot" for biter nests. For bonus points, the angry ghost deconstruction planner will add "shoot" to biter nests, marking them for aggressive deconstruction. These options unlock at captivity and aren't really meaningful before that point.