Revise and enhance enemies

[Qatavin]

Makes various revisions to how enemy units and entities work to improve balance and patch some oversights.

Reduces Leviathan health a bit to make them less difficult to handle.
Allows Hardened Bile to be picked up by Construction Robots. Basic faction worms will now make Hardened Bile spawn with their attacks.
Adds ignore_collision_condition in several places where it was missing, allowing those attacks to hit flying robots.
Adds a new invisible homing attack to Piercing Worms that can only hit flying robots. Previously, they were completely incapable of hitting flying robots at all. The Piercing faction is meant to be weak to those bots, but not that weak.
Adds a little something to the Electric faction's bile pools so they zap flying robots in an area. This faction is very much meant to be strong against bots, but the range of the pools was too small to be effective.
Revises Poison faction to significantly increase friendly healing from smoke clouds.
Makes a few adjustments to enemies' Laser resistance. Worms weak to Lasers will now be not quite so weak. I also revised the table for worms with very high Laser resistance (though no faction has this trait).
Removes redundant line adding "not-fire-unit" mask to units (it was being done twice).

Revises flying robots (combat and logistic/construction) by giving them a strong Poison resistance. Increases Laser Robot health from 100 to 150. Also fixes its order to bring it in line with the other flying combat bots.