Kill the light client, CHTs and change tries. (#10080)

* Remove light client, change tries and CHTs

* Update tests

* fmt

* Restore changes_root

* Fixed benches

* Cargo fmt

* fmt

* fmt

substrate/client/rpc/src/chain/mod.rs

@@ -19,7 +19,6 @@
 //! Substrate blockchain API.
 
 mod chain_full;
-mod chain_light;
 
 #[cfg(test)]
 mod tests;
@@ -33,10 +32,7 @@ use rpc::{
 use std::sync::Arc;
 
 use jsonrpc_pubsub::{manager::SubscriptionManager, typed::Subscriber, SubscriptionId};
-use sc_client_api::{
-	light::{Fetcher, RemoteBlockchain},
-	BlockchainEvents,
-};
+use sc_client_api::BlockchainEvents;
 use sp_rpc::{list::ListOrValue, number::NumberOrHex};
 use sp_runtime::{
 	generic::{BlockId, SignedBlock},
@@ -204,29 +200,6 @@ where
 	Chain { backend: Box::new(self::chain_full::FullChain::new(client, subscriptions)) }
 }
 
-/// Create new state API that works on light node.
-pub fn new_light<Block: BlockT, Client, F: Fetcher<Block>>(
-	client: Arc<Client>,
-	subscriptions: SubscriptionManager,
-	remote_blockchain: Arc<dyn RemoteBlockchain<Block>>,
-	fetcher: Arc<F>,
-) -> Chain<Block, Client>
-where
-	Block: BlockT + 'static,
-	Block::Header: Unpin,
-	Client: BlockBackend<Block> + HeaderBackend<Block> + BlockchainEvents<Block> + 'static,
-	F: Send + Sync + 'static,
-{
-	Chain {
-		backend: Box::new(self::chain_light::LightChain::new(
-			client,
-			subscriptions,
-			remote_blockchain,
-			fetcher,
-		)),
-	}
-}
-
 /// Chain API with subscriptions support.
 pub struct Chain<Block: BlockT, Client> {
 	backend: Box<dyn ChainBackend<Client, Block>>,