State used for error state
it will be emitted when there is a catched error on the query fetch function
it contains the error catched in the query fetch function
State used for loading state
it will be the inital state when every query stream is created
it will be the inital state when every query stream is invalidated
extend this class to declare your queries
implement the key getter returning an unique id for the query
implement the fetch method returning data or errors