More sync updates (#1791)

## Issue Addressed
#1614 and a couple of sync-stalling problems, the most important is a cyclic dependency between the sync manager and the peer manager

beacon_node/network/src/sync/range_sync/mod.rs

@@ -10,3 +10,4 @@ mod sync_type;
 pub use batch::BatchInfo;
 pub use chain::{BatchId, ChainId, EPOCHS_PER_BATCH};
 pub use range::RangeSync;
+pub use sync_type::RangeSyncType;