Capturable husks for all mods

as this is an interesting game mechanic in Tiberium Wars and it also solves the problem of indestructible wrecks blocking vital cells. Tested it against bots (https://github.com/OpenRA/OpenRA/commit/1a33608b73602338663f7200c65fb12bdc2656c7 seems sufficient) and a second client on the same server (no desyncs).