This commit allows DNS names to be used when specifying the endpoint
for a node in the WireGuard mesh. This is useful in many scenarios, in
particular when operating an IoT device whose public IP is dynamic. This
change allows the administrator to use a dynamic DNS name in the node's
endpoint.
One of the side-effects of this change is that the WireGuard port can
now be specified individually for each node in the mesh, if the
administrator wishes to do so.
*Note*: this commit introduces a breaking change; the
`force-external-ip` node annotation has been removed; its functionality
has been ported over to the `force-endpoint` annotation. This annotation
is documented in the annotations.md file. The expected content of this
annotation is no longer a CIDR but rather a host:port. The host can be
either a DNS name or an IP.
Signed-off-by: Lucas Servén Marín <lserven@gmail.com>
