consensus/clique, internal/web3ext: support hash based API queries (#14321)

* consensus/clique, internal/web3ext: support hash based API queries

* consensus/clique: make RPC return types public

consensus/consensus.go

@@ -40,6 +40,9 @@ type ChainReader interface {
 	// GetHeaderByNumber retrieves a block header from the database by number.
 	GetHeaderByNumber(number uint64) *types.Header
 
+	// GetHeaderByHash retrieves a block header from the database by its hash.
+	GetHeaderByHash(hash common.Hash) *types.Header
+
 	// GetBlock retrieves a block from the database by hash and number.
 	GetBlock(hash common.Hash, number uint64) *types.Block
 }