Events have not good implementations of equals(), hashCode() and toString()

[Janmm14]

Many events have neither of the three and a toString() call is for example handled by PlayerEvent class, which prints PlayerEvent and not the actual event subclass. Additionally CancellablePlayerEvent and InventoryTransactionEvent as examples are ignoring fields from its super class in its toString().

I suggest removing custom equals and hashCode implementations from events as there is no reason to save and compare event instances.

Also toString() methods should be updated and added to all events to include super class fields like player or entity and cancelled.