Add a LibP2P instantiation to coordinator

It's largely unoptimized, and not yet exclusive to validators, yet has basic
sanity (using message content for ID instead of sender + index).

Fixes bugs as found. Notably, we used a time in milliseconds where the
Tributary expected  seconds.

Also has Tributary::new jump to the presumed round number. This reduces slashes
when starting new chains (whose times will be before the current time) and was
the only way I was able to observe successful confirmations given current
surrounding infrastructure.

tests/coordinator/src/lib.rs

@@ -38,6 +38,10 @@ pub fn coordinator_instance(
         use serai_client::primitives::insecure_pair_from_name;
         hex::encode(&insecure_pair_from_name(name).as_ref().secret.to_bytes()[.. 32])
       }),
+      (
+        "RUST_LOG".to_string(),
+        "serai_coordinator=trace,".to_string() + "tributary_chain=trace," + "tendermint=trace",
+      ),
     ]
     .into(),
   )