The engine doesn't throw an error if it has no name

[sebastienfilion]

Trying to instantiate an engine without a name doesn't throw an error, but part of the initialization code expects the value to be set.

const $engine = new NucleusEngine();

This throws a Nucleus Datastore error NucleusError: The item must be a string.

The name should be mandatory and throw a clear error when omitted.

[sebastienfilion]

The Nucleus Datastore has a default name (Undefined), this isn't a problem because the name are just used for debugging. In the case of the engine, it could become a problem to have a default name because the engine's main queue's name is the name of the engine...

So, if the user instantiate different engine named Undefined, all the action would be pushed to the Undefined queue and would cause a lot of confusion.