* FENIX-163 get distinct field values

* [FENIX-163] add aggregate count and distinct unit tests

* [FENIX-163] add aggregate methods to CrudController and BaseCrudRestClient

* [FENIX-163] add multiple fields test cases

* [FENIX-163] rename aggregate to aggregation

* [FENIX-163] rename class DistinctValue to AggregationResultValue

* Aggregate

* [FENIX-345] Aggregation fixes

* [FENIX-345] Aggregation : PR return

Co-authored-by: Mounir Nayab <mounir.nayab@xelians.fr>
Co-authored-by: Makhtar DIAGNE <makhtar.diagne@teamdlab.com>
Co-authored-by: Hicham Barhoumi <hicham.barhoumi@archiveco.fr>