[WIP] import static cloud information (service)

[lpuskas]

The PR relates to #147, it is WIP yet!

• added draft service data definition (it reflects the currently stored data, no optimisations or other improvements have been done to it)
• service and provider related validation has been amended (validation done against data in the store services also stored in the store)
• service related operations have been abstracted from the "infoers", these are handled in the CloudInfo implementation
• services are loaded in the store during startup, from a configurable yaml file
• introduced the notion of 'static service' -these are excluded from the automatic refresh operation

As per the current status a new 'static service' can be added/imported to a given (supported) provider;
and it's working along with the usual services

TBD:

• where to keep the service definition file and the service information data file
• how to drive the import (configuration / automatic triggering etc ...)
• optimize the data file structure to reduce redundancies (eg.: add flags to entities that are the same between services / regions etc ...)
• refine requirements (custom infoer - no cloud provider implied)

[lpuskas]

changes in this PR have already been merged - copied over to other PRs