Fix Application Storage ownership

Application storage should be owned by application system and then it should be given to anyone interested in it (including Application Service).
The benefits:
- those who need storage but do not need service now are able to get it from ApplicationSystem directly
- initialization order of storage and service is easier to handle (now it is being handled from the generic place - ApplicationSystem)
- we're decoupling storage and service and ApplicationService interface can be cleaned from unneeded methods.