SE-127 tests for AggregateFunction, PhosphoNetXServer, and TreatmentFinder added

.../openbis/plugin/phosphonetx/server/PhosphoNetXServer.java

.../plugin/phosphonetx/server/business/ProteinDetailsBO.java

...osphonetx/server/business/ProteinWithAbundancesTable.java

...enbis/plugin/phosphonetx/server/business/SampleTable.java

...s/plugin/phosphonetx/server/business/TreatmentFinder.java

...sphonetx/client/web/client/dto/AggregateFunctionTest.java

...x/cisd/openbis/plugin/phosphonetx/server/MockDataSet.java

...nbis/plugin/phosphonetx/server/PhosphoNetXServerTest.java

...ugin/phosphonetx/server/business/TreatmentFinderTest.java