* utils: fix #16138 by checking if vhosts flag is set

* utils,node: fix defaults for rpcvhosts

* node,utils: address review concerns

* go-metrics: fork library and introduce ResettingTimer and InfluxDB reporter.

* vendor: change nonsense/go-metrics to ethersphere/go-metrics

* go-metrics: add tests. move ResettingTimer logic from reporter to type.

* all, metrics: pull in metrics package in go-ethereum

* metrics/test: make sure metrics are enabled for tests

* metrics: apply gosimple rules

* metrics/exp, internal/debug: init expvar endpoint when starting pprof server

* internal/debug: tiny comment formatting fix

* cmd,node,rpc: add allowedHosts to prevent dns rebinding attacks

* p2p,node: Fix bug with dumpconfig introduced in r54aeb8e4c0bb9f0e7a6c67258af67df3b266af3d

* rpc: add wildcard support for rpcallowedhosts + go fmt

* cmd/geth, cmd/utils, node, rpc: ignore direct ip(v4/6) addresses in rpc virtual hostnames check

* http, rpc, utils: make vhosts into map, address review concerns

* node: change log messages to use geth standard (not sprintf)

* rpc: fix spelling

This commit affects p2p/discv5 "topic discovery" by running it on
the same UDP port where the old discovery works. This is realized
by giving an "unhandled" packet channel to the old v4 discovery
packet handler where all invalid packets are sent. These packets
are then processed by v5. v5 packets are always invalid when
interpreted by v4 and vice versa. This is ensured by adding one
to the first byte of the packet hash in v5 packets.

DiscoveryV5Bootnodes is also changed to point to new bootnodes
that are implementing the changed packet format with modified
hash. Existing and new v5 bootnodes are both running on different
ports ATM.

p2p/simulations: introduce dialBan

- Refactor simulations/network connection getters to support
  avoiding simultaneous dials between two peers If two peers dial
  simultaneously, the connection will be dropped to help avoid
  that, we essentially lock the connection object with a
  timestamp which serves as a ban on dialing for a period of time
  (dialBanTimeout).

- The connection getter InitConn can be wrapped and passed to the
  nodes via adapters.NodeConfig#Reachable field and then used by
  the respective services when they initiate connections. This
  massively stablise the emerging connectivity when running with
  hundreds of nodes bootstrapping a network.

p2p: add Inbound public method to p2p.Peer

p2p/simulations: Add server id to logs to support debugging
in-memory network simulations when multiple peers are logging.

p2p: SetupConn now returns error. The dialer checks the error and
only calls resolve if the actual TCP dial fails.

This commit introduces a network simulation framework which
can be used to run simulated networks of devp2p nodes. The
intention is to use this for testing protocols, performing
benchmarks and visualising emergent network behaviour.