Avoid duplicate property names

[bitbrain]

It is currently possible to create scenarios where property names can exist multiple times within an entity, leading to undesired behavior. Any property name should be unique per entity.

• a parent entity cannot define a property that already exists on a child
• a child entity cannot define a property that got inherited from a parent
• an entity should not have the same property twice, meaning renaming one property to an already existing name should not be possible

[FonkinS]

So would the best method be to have a signal in the property resource, that calls its 'owner' category/entity to check if it has another property with that name? And then signal back to the property whether it's valid or not? Although I'm not sure if this kind of two way signalling is the best idea.