Improve service container

[lukas-schardt]

47 introduced the system of a service container to let the luna-js user override services inside luna-js. This service container can be used for other luna core services to allow overriding and easier testing.

• Put every core service where it could make sense to inject inside the service container
• Allow for service injection & service registration by using the proposed decorator functions
• Find a central place to register service ids

Proposed patterns:

@LunaService({
    name: 'DocumentRenderer'
})
export default class DocumentRenderer {

}

[lukas-schardt]

Closed by #53