* Enable content cache for state network.
* Update state json-rpc endpoints to return local content which uses cache if enabled.
* Add content cache metrics.
* Make content cache configurable.
* Add content cache tests.
The revalidateMax value is lowered to have a quicker ramp up of
the radiusCache + to keep it healthier.
The defaultMaxGossipNodes value is lowered because with the
current value a Nodes lookup is triggered almost always.
This value is dependant on the content replication value. This
is dependant on the network (and subnetwork) because of the amount
of nodes and their radius/storage capacity.
This avoid restarting the node always with a full radius, which
causes the node the be bombarded with offers which it later has
to delete anyhow.
In order to implement this functionality, several changes were
made as the radius needed to move from the Portal wire protocol
current location to the contentDB and beaconDB, which is
conceptually more correct anyhow.
So radius is now part of the database objects and a handler is
used in the portal wire protocol to access its value.
* Add nph check to fluffy CI lint
* Add a section on nph usage in the fluffy.guide
* Update copyright years for altered files
* Avoid chained methods formatting style in db code
* Update nph in CI to v0.5
* Remove leftover commented import
* Move comment to avoid nph turning complex list into simple list (nph bug)
* Update nph in CI to v0.5.1
* Formatting fluffy with nph v0.5.1
* Reduce Nim 1.6 compiler warnings/hints for Fluffy and Nimbus proxy
Mostly raises Defect removals, TaintedString removal and some
unnecessary imports.
Also updating the copyright years alongside.
* Further reduce Nim 1.6 compiler warnings/hints for Nimbus
bhartnett
Kim De Mey
web3-developer
Daniel Sobol
andri lim
KonradStaniec