Merge pull request #1777 from lexe-tech/max/best-block-header-best-block

Add `.to_best_block()` method to `ValidatedBlockHeader`

diff --cc lightning-block-sync/src/poll.rs
index d45e900bad0b3733da3335cd9415001bd4c9a558,1243d004aae7a2b56f8ac851624ab0c531f326eb..05ccd4504fde0d81a76646d91b44d9b2b1653711
--- 1/lightning-block-sync/src/poll.rs
--- 2/lightning-block-sync/src/poll.rs
+++ b/lightning-block-sync/src/poll.rs
@@@ -1,9 -1,11 +1,10 @@@
  //! Adapters that make one or more [`BlockSource`]s simpler to poll for new chain tip transitions.
  
 -use crate::{AsyncBlockSourceResult, BlockHeaderData, BlockSource, BlockSourceError, BlockSourceResult};
 +use crate::{AsyncBlockSourceResult, BlockData, BlockHeaderData, BlockSource, BlockSourceError, BlockSourceResult};
  
 -use bitcoin::blockdata::block::Block;
  use bitcoin::hash_types::BlockHash;
  use bitcoin::network::constants::Network;
+ use lightning::chain::BestBlock;
  
  use std::ops::Deref;