refactor!: Move ConnectionId and PendingPoint to libp2p-swarm (#3346)

Both of these are only needed as part of `libp2p-swarm`. Them residing in `libp2p-core` is a left-over from when `libp2p-core` still contained `Pool`.

core/src/connection.rs

@@ -20,29 +20,6 @@
 
 use crate::multiaddr::{Multiaddr, Protocol};
 
-/// Connection identifier.
-#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
-pub struct ConnectionId(usize);
-
-impl ConnectionId {
-    /// Creates a `ConnectionId` from a non-negative integer.
-    ///
-    /// This is primarily useful for creating connection IDs
-    /// in test environments. There is in general no guarantee
-    /// that all connection IDs are based on non-negative integers.
-    pub fn new(id: usize) -> Self {
-        Self(id)
-    }
-}
-
-impl std::ops::Add<usize> for ConnectionId {
-    type Output = Self;
-
-    fn add(self, other: usize) -> Self {
-        Self(self.0 + other)
-    }
-}
-
 /// The endpoint roles associated with a peer-to-peer communication channel.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum Endpoint {
@@ -75,42 +52,6 @@ impl Endpoint {
     }
 }
 
-/// The endpoint roles associated with a pending peer-to-peer connection.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum PendingPoint {
-    /// The socket comes from a dialer.
-    ///
-    /// There is no single address associated with the Dialer of a pending
-    /// connection. Addresses are dialed in parallel. Only once the first dial
-    /// is successful is the address of the connection known.
-    Dialer {
-        /// Same as [`ConnectedPoint::Dialer`] `role_override`.
-        role_override: Endpoint,
-    },
-    /// The socket comes from a listener.
-    Listener {
-        /// Local connection address.
-        local_addr: Multiaddr,
-        /// Address used to send back data to the remote.
-        send_back_addr: Multiaddr,
-    },
-}
-
-impl From<ConnectedPoint> for PendingPoint {
-    fn from(endpoint: ConnectedPoint) -> Self {
-        match endpoint {
-            ConnectedPoint::Dialer { role_override, .. } => PendingPoint::Dialer { role_override },
-            ConnectedPoint::Listener {
-                local_addr,
-                send_back_addr,
-            } => PendingPoint::Listener {
-                local_addr,
-                send_back_addr,
-            },
-        }
-    }
-}
-
 /// The endpoint roles associated with an established peer-to-peer connection.
 #[derive(PartialEq, Eq, Debug, Clone, Hash)]
 pub enum ConnectedPoint {