Add the new metadata struct to EthereumTransaction

Author: mloit

Sources/web3swift/Transaction/EthereumTransaction.swift

@@ -14,6 +14,10 @@ public struct EthereumTransaction: CustomStringConvertible {
     /// and type specific implementation
     internal var envelope: AbstractEnvelope
 
+    /// storage container for additional metadata returned by the node
+    /// when a transaction is decoded form a JSON stream
+    public var meta: EthereumMetadata?
+
     // convenience accessors to the common envelope fields
     // everything else should come from getOpts/setOpts
     /// The type of the transacton being represented, see TransactionType enum
@@ -227,6 +231,8 @@ extension EthereumTransaction: Decodable {
     public init(from decoder: Decoder) throws {
         guard let env = try EnvelopeFactory.createEnvelope(from: decoder) else { throw Web3Error.dataError }
         self.envelope = env
+        // capture any metadata that might be present
+        self.meta = try EthereumMetadata(from: decoder)
     }
 }