transport: Reject secondary connections with different connection IDs (#176)

This PR ensures that the transport manager rejects secondary
connections.

When the secondary connection is rejected, the internal `dial_record` is
preserved.

Added a test to validate this behavior, with multiple wrong endpoints.

Part of: #172
Will keep the issue opened for to further into it. 

cc @paritytech/networking

---------

Signed-off-by: Alexandru Vasile <[email protected]>

Author: lexnv

src/transport/manager/address.rs

@@ -34,7 +34,7 @@ pub struct AddressRecord {
     /// Address.
     address: Multiaddr,
 
-    /// Connection ID, if specifed.
+    /// Connection ID, if specified.
     connection_id: Option<ConnectionId>,
 }