Currently if a banned node tries to connect to a cluster it fails to
create connections, but has no idea why, so from inside the node it
looks like it has communication problems. This patch adds new rpc
NOTIFY_BANNED which is sent back to the node when its connection is
dropped. On receiving the rpc the node isolates itself and print an
informative message about why it did so.
Closesscylladb/scylladb#26943
The patch adds new marker for a verb - [[ip]] that means that for this
verb ip version of the verbs needs to be generated. Most of the verbs
do not need it.
The `join_node_request` and `join_node_response` RPCs are added:
- `join_node_request` is sent from the joining node to any node in the
cluster. It contains some initial parameters that will be verified by
the receiving node, or the topology coordinator - notably, it contains
a list of cluster features supported by the joining node.
- `join_node_response` is sent from the topology coordinator to the
joining node to tell it about the the outcome of the verification.
