*: Dial with handler and return handler on error and closed (#2191)

Require `NetworkBehaviourAction::{DialPeer,DialAddress}` to contain a
`ProtocolsHandler`. This allows a behaviour to attach custom state to its
handler. The behaviour would no longer need to track this state separately
during connection establishment, thus reducing state required in a behaviour.
E.g. in the case of `libp2p-kad` the behaviour can include a `GetRecord` request
in its handler, or e.g. in the case of `libp2p-request-response` the behaviour
can include the first request in the handler.

Return `ProtocolsHandler` on connection error and close. This allows a behaviour
to extract its custom state previously included in the handler on connection
failure and connection closing. E.g. in the case of `libp2p-kad` the behaviour
could extract the attached `GetRecord` from the handler of the failed connection
and then start another connection attempt with a new handler with the same
`GetRecord` or bubble up an error to the user.

Co-authored-by: Thomas Eizinger <thomas@eizinger.io>

misc/metrics/src/swarm.rs

@@ -230,7 +230,7 @@ enum PendingConnectionError {
     InvalidPeerId,
     TransportErrorMultiaddrNotSupported,
     TransportErrorOther,
-    ConnectionLimit,
+    Aborted,
     Io,
 }
 
@@ -248,8 +248,8 @@ impl<TTransErr> From<&libp2p_core::connection::PendingConnectionError<TTransErr>
             libp2p_core::connection::PendingConnectionError::Transport(
                 libp2p_core::transport::TransportError::Other(_),
             ) => PendingConnectionError::TransportErrorOther,
-            libp2p_core::connection::PendingConnectionError::ConnectionLimit(_) => {
-                PendingConnectionError::ConnectionLimit
+            libp2p_core::connection::PendingConnectionError::Aborted => {
+                PendingConnectionError::Aborted
             }
             libp2p_core::connection::PendingConnectionError::IO(_) => PendingConnectionError::Io,
         }