Extract constant
ISPN-4416 Implement sorting and pagination for non-indexed querying (phase I)

This is a simple implementation that sorts all the results just before returning them to the requestor. A second implementation will be provided based on ISPN-4358 when it becomes available.
Most of the failing non-indexed query tests are solved by this.

* Also adds *QueryDslconditionsTest.testInvalidEmbeddedAttributeQuery() to prove ISPN-4423 happens only in remote lucene based mode, but not in the other modes
* Add param validation and tests for pagination for both indexed and non-indexed sorting
ISPN-4425 Validate format of comparison operands (non-indexed query)

* Validate operand format for numeric properties
* Validate operand for embedded entities -> do not allow such predicates
ISPN-4414 Compatible failover request load balancer for HR clients
ISPN-4414 Update documentation to use new request balancing interface