Make the agent mapping list of configuration docs filterable

[mariusoe]

Currently, users can select an agent mapping in the "configuration docs"-view of the configuration ui in order to show a configuration documentation of it. The list of agent mappings is not sorted and cannot be filtered which makes it really hard to use in case many agent mappings are existing.

In this ticket, the list of agent mapping should be sorted and a possibility should be created so that it can be filtered as well.