Moved VolatileStorage to test bundle.
Removed StorageSelector and refactored managed provider to use one service only.
Adapted tests.

Signed-off-by: Dennis Nobel <d.nobel@external.telekom.de>
Enhanced StorageService interface to take ClassLoader as second argument.
Using getService with ClassLoader in ManagedItemChannelLinkProvider, ManagedItemProvider and ManagedThingProvider.
Added transient modifier to fields, that must not be persisted.

Signed-off-by: Dennis Nobel <d.nobel@external.telekom.de>