Add a field for getting the exact(float) clicked position, which can be used for detecting the clicked slot of a chiseled bookshelf.

On current version, there's only interacted block position, so we have to use `player.getEyeLocation().getDirection()` and impl a method to reach the block in order to get the final clicked position. However it's not safe, because of the latency. The result we get is not equal with the client sends.

Wrap the Vec3D in MovingObjectPositionBlock will return a safe, accurate position.