Update deprecated API usages after upgrade to hibernate-search 4.4.0.Alpha1
ISPN-3333 Rework query DSL implementation

* Add implemenation for sorting and projections
* Implement missing operators after HQL parser upgrade
* Implement query for enum attributes
* Refactor AttributeCondition into separate classes to represent each operator to be able to fully use the visitor pattern and avoid explicit switch statements
* Add more DSL tests to cover more cases for the sample domain model