Extend configuration server's agent status by the used branch

[mariusoe]

Currently, the agent status list which is provided by the configuration server provides information which agent has received which agent mapping. In the current state, this information only contains the name of the used agent mapping. Since the configuration server has the ability to use the working or live branch for the basis of an agent mapping, this information should also be included in the status.

In this ticket, the provided agent status information of the configuration server should be extended to include also the branch which was used to deliver a certain agent mapping.