Broadcast for slots (#2081)

* Insert blobs into db_ledger in broadcast stage to support leader to validator transitions

* Add transmitting real slots to broadcast stage

* Handle real slots instead of default slots in window

* Switch to dummy repair on slots and modify erasure to support leader rotation

* Shorten length of holding locks

* Remove logger from replicator test

tests/multinode.rs

@@ -1056,8 +1056,10 @@ fn test_leader_validator_basic() {
     }
 
     // Shut down
-    validator.close().unwrap();
-    leader.close().unwrap();
+    validator
+        .close()
+        .expect("Expected successful validator close");
+    leader.close().expect("Expected successful leader close");
 
     // Check the ledger of the validator to make sure the entry height is correct
     // and that the old leader and the new leader's ledgers agree up to the point