A small change to simplify the methodology of selecting mock resultsets from MockDataProviders

These changes add new options for SelectableMockConnection and SelectableMockDataProvider which allow the end user to use a selector method on the SelectorMockConnection which in turn updates a selector field inside of the SelectableMockDataProvider such that the value of the selector field can be used to choose the results returned from the SelectableMockDataProvider. This simplifies configuring mock result sets for unit testing jOOQ applications.