Get rid of `cloakCost{,Moving}`

It doesn't actually do anything (the engine does NOT use it for cloak costs), other than being re-exposed for reading back by Lua which is what customparams are for. Make PRs to games (incl. ancillaries like Circuit/Barbarian AI) first though since it should be trivial to do so.

Start by searching the engine and game integrations for `cloakCost` and `cloakCostMoving`, including the named Circuit and Barbarian AI ancillaries. First update the affected games and ancillaries as requested, then remove the unused engine exposure and verify that Lua customparams still provide the intended readback.

Written by the indexing model from the issue text.