move-only: Move CBlockTreeDB to node/blockstorage

The block index (CBlockTreeDB) is required to write and read blocks, so
move it to blockstorage. This allows to drop the txdb.h include from
`node/blockstorage.h`.

Can be reviewed with:

--color-moved=dimmed-zebra  --color-moved-ws=ignore-all-space

1 files changed, 0 insertions, 1 deletions

diff --git a/src/validation.h b/src/validation.h
index d7ad86a5e8..8a3ba69f59 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -47,7 +47,6 @@
 #include <vector>
 
 class Chainstate;
-class CBlockTreeDB;
 class CTxMemPool;
 class ChainstateManager;
 struct ChainTxData;