Bulk actions

[olegshegai]

Extend law system as it was described here: https://github.com/StrangeLoopGames/Eco/pull/6740#discussion_r484571527

[johnkslg]

Some notes on this one:

• Main change for this one is to make IPositionGameAction provide an IEnumerable instead of a Vector3i alone.
• Can introduce an ICountableAction, and that count should be exposed as a context property in the actions that implement it.