Actions

[JohnoRobson]

Added an "Action System" to the game. This is a way to structure the actions that GameItems can do, such as heal, be thrown, do a raycast and damage an actor if they're hit, etc, in a way that allows for code reuse and easy iteration for making new GameItems using existing behaviours.

GameItems now have an Action that they trigger and send to the ActionSystem when they are used. Actions are Resources that can hold other Actions within them, forming a tree of Actions that the ActionSystem iterates over and makes their effects happen. For examples, look at any of the item or weapon scenes.

Also, added a grenade model and an explosion effect/scene.

[morganwynne]

• [x] Rename scripts/items/aim_function.gd script to better represent lobbing aiming.