Add event to create actual queries searched with

[gisostallenberg]

At the moment the queries are created as shown in the images below.
By dispatching an event that will create the queries, the bundle would become more flexible and it would for example allow to implement fuzzy queries, or anything more advanced.

Another way to allow more flexibility is to extract the search method of the adapter into two stages, creating the query prepareSearch and running it executeQuery. Extending the massive_search.adapter would be much easier that way.

[alexander-schranz]

Events I think currently are difficult to handle at this case as they should not be adapter specific. I'm fine if we add some protected functions like prepareSearch and executeSearch into both adapters to make it easy to override this service functionality.