Start reading available attributes from ABI

pkg/core/blockchain.go

@@ -5,5 +5,6 @@ type Blockchain interface {
 	SubscribeToBlocks(blocks chan Block)
 	StartListening()
 	StopListening()
+	GetContractAttributes(contractHash string) ([]ContractAttribute, error)
 	GetContractStateAttribute(contractHash string, attributeName string) (*string, error)
 }

pkg/core/watched_contract.go

@@ -4,3 +4,8 @@ type WatchedContract struct {
 	Hash         string
 	Transactions []Transaction
 }
+
+type ContractAttribute struct {
+	Name string
+	Type string
+}