feat: use item activation (right click) for magic staff

[skaldarnar]

This PR makes use of the PRs referenced below to turn the magic staff weapon into an item that is used with "item activation", i.e., right click. As the staff is supposed to be used on range against another player this use case needs to be supported by the engine.

It improves the game play in the sense that using the staff is now similar to using the bow or the fire ball staff instead of a "ranged use" action (as in, opening a door with e).

• the staff's effect currently is instant. if we want to nerf it in the future, e.g., by requiring a player to track the enemy flag bearer for some time t, how can we do this with the technical foundation we have here? does the activation event help here, or do we need something different?

Depends on MovingBlocks/Terasology#4818 Depends on Terasology/LightAndShadowResources#70

[ahv15]

It might be a good idea to shift the staff to the shop (once it's added) instead as now players can remove the flag even without the staff and having a larger range (the staff) shouldn't be the default behavior (as all the players could camp and prevent others from bringing the flag back) and making sure that the player tracks the opponent would probably be necessary (not sure whether occasionally checking whether the target is being detected during the time period would be the right thing to do) as the weapon might be too powerful based on the range.