Use Go's new fuzz tooling instead of go-fuzz

Use Go's new fuzz tooling instead of go-fuzz

Add a permission handler to filter client requests

Another attempt to address pion#134, see an earlier attempt in
pion#222. pion#222 introduces the DeniedPeerRange stanza into the
ServerConfig to implement peer address blacklisting. This approach has
a couple of issues: (1) it implements only peer blacklists, but does
not allow whiletelisting or filtering based on DNS, etc.;(2) it handles
only the ChannelBindRequest codepath, but leaves the CreatePermission
codepath (https://datatracker.ietf.org/doc/html/rfc8656#section-3.4)
open; and it introduces a new package dependency on "inet.af/netaddr".

This patch takes a different approach: it allows the user to specify a
PermissionHandler callback for each PacketConnConfig/ListenerConfig in
the ServerConfig. Whenever a permission is about to be created via the
associated PacketConn/Listener (either via a ChannelBindRequest or a
CreatePermission), the PermissionHandler is called with the requested
peer address and it can decide whether to accommodate the permission
request (return boolean true) or deny it (return false). In the latter
case, a "permission request administratively prohibited" error is
returned to the client.

Also added tests and an example.

Update CI configs to v0.8.1

Update lint scripts and CI configs.

Fix lint

fix lint

Add CreatePermission method to TURN client

Allow clients to create Permissions without calling Write

Update CI configs to v0.6.4

Update lint scripts and CI configs.

Add RelayAddressGeneratorPortRange

New RelayAddressGenerator that only listens in a certain range

Update module stretchr/testify to v1.6.1

Generated by renovateBot

Transaction result blocking send

This fixes a race condition where a transaction result could attempt to
send on the result channel before it had a receiver (i.e. before
transaction.WaitForResult has been called), causing the caller to never
see the result. This was very likely to occur when when two peers and
the STUN/TURN server were on the same host.

Fix send on closed channel in Client

Protect concurrent run of
trMap.Find, trMap.CloseAndDeleteAll, and trMap.Delete.