HealthCheck that builds on-top of DocumentNodeStore's
determineServerTimeDifferenceMillis method which checks how much the local
time differs from the DocumentStore's time. It then applies low- and
high-water marks to that time difference:
- if the value is higher than the high-water mark (5sec by default), then
it issues a critical
- if the value is lower than the high-water but higher than the low-water
mark (1sec by default), then it issues only a warn
- if the value is lower than the low-water mark, then it issues only an
info