Rename "chain" module to "blockchain".

src/node/client.rs

@@ -6,7 +6,7 @@ use smol::Executor;
 use url::Url;
 
 use crate::{
-    chain::{rocks::columns, Rocks, RocksColumn, Slab},
+    blockchain::{rocks::columns, Rocks, RocksColumn, Slab},
     crypto::{
         address::Address,
         coin::Coin,

src/node/service/gateway.rs

@@ -10,7 +10,7 @@ use url::Url;
 
 use super::reqrep::{PeerId, Publisher, RepProtocol, Reply, ReqProtocol, Request, Subscriber};
 use crate::{
-    chain::{rocks::columns, RocksColumn, Slab, SlabStore},
+    blockchain::{rocks::columns, RocksColumn, Slab, SlabStore},
     util::serial::{deserialize, serialize},
     Error, Result,
 };

src/node/state.rs

@@ -2,7 +2,7 @@ use incrementalmerkletree::{bridgetree::BridgeTree, Frontier, Tree};
 use log::{debug, error};
 
 use crate::{
-    chain::{rocks::columns, RocksColumn},
+    blockchain::{rocks::columns, RocksColumn},
     crypto::{
         coin::Coin,
         keypair::{PublicKey, SecretKey},