Merge pull request #5753 from Icinga/fix/ringbuffer-does-not-get-updated-if-nothing...

Fix that RingBuffer does not get updated and add metrics about communication between endpoints

diff --cc lib/base/workqueue.cpp
Simple merge

diff --cc lib/base/workqueue.hpp
Simple merge

diff --cc lib/db_ido/dbconnection.cpp
Simple merge

diff --cc lib/icinga/cib.cpp
Simple merge

diff --cc lib/methods/clusterzonechecktask.cpp
Simple merge

diff --cc lib/remote/apilistener.cpp
Simple merge

diff --cc lib/remote/endpoint.cpp
Simple merge

diff --cc lib/remote/jsonrpcconnection.cpp
Simple merge