#299 who closed#133 did not take into account, that that gitea (and eventually) other forges do return 200 and empty string if file was not found - this make configFetcher more resilient
* move api code to server/api
* move grpc server for agent communication to server/grpc
* move server.Config to server/config.go as it is used by both server/api and server/grpc
* move shared code used by server/api and server/grpc to server/shared
