Added service combiners for easier extensibility

--HG--
rename : Main/Source/NMemory/Services/KeyInfoFactoryServiceBase.cs => Main/Source/NMemory/Services/CombinedKeyInfoFactoryService.cs
rename : Main/Source/NMemory/Services/KeyInfoHelperFactoryServiceBase.cs => Main/Source/NMemory/Services/CombinedKeyInfoHelperFactoryService.cs