Introduce Hallway namespace

Hallway will be the "Entry point" for further foreign plants
Introducing of the multiple workhorses, refactoring.
IPlantEx add helper method for workhorses
Fix existing services to take delegation into account
Fix mock type
Extend IPlant interface
Fix mock to allow building
Rename Set to Store for service interfaces
Fix mock to build
Introduce user config service and its interfaces
Introduce thread context and switchers
Make Switcher Dispose() method virtual
Introduce BulkSettingsUpdate context
Modify ServicesSteward to use BulkSettingsUpdateContext
Add resolvers based object factory
Introduce User config service v2
Add test