Add option to manage the spread behavior

[Leirof]

By default, the system will teleport the player on the highest block in the defined area.

We can imagine an option that, according to the value, change this behavior such as:

• 0: Default behavior
• 1: Teleport the entity on top of a block, but not always the highest one
• 2: Teleport the entity randomly in the area without considering the blocks