Exposed Lua engine handlers for dropping and placing objects

!5288 (merged)

Lua should have the ability to handle any actors dropping items and the player placing items (clicking an inventory item and placing in a specific location).

  • onDropped (for all actors)
  • onPlaced (for the player)

This will allow mods that currently use onFrame or onUpdate listening to have dedicated handlers. Largely, mods that handle "perfect placement" situations.