Component/worker resolution exposed on the API and through host functions

[vigoo]

Resolving component ID or even worker ID given name-based information or URN, available as an API and Golem host function.

[mschuwalow]

Component names might be not unique. Check during implementation

[mschuwalow]

ComponentName -> ComponentId
(ComponentName, WorkerName) -> WorkerURN

(and whatever needs to be added to make use-site nice)