web3.js: Introduce support for log messages inside ConfirmedTransactionMeta. (#12629)

* feat: add logMessages to ConfirmedTranasactionMeta

* feat: add flow type and additional superstruct validators

web3.js/module.d.ts

@@ -141,6 +141,7 @@ declare module '@solana/web3.js' {
     fee: number;
     preBalances: Array<number>;
     postBalances: Array<number>;
+    logMessages?: Array<string>;
     err: TransactionError | null;
   };
 

web3.js/module.flow.js

@@ -155,6 +155,7 @@ declare module '@solana/web3.js' {
     fee: number,
     preBalances: Array<number>,
     postBalances: Array<number>,
+    logMessages?: Array<string>,
     err: TransactionError | null,
   };
 

web3.js/src/connection.js

@@ -374,12 +374,14 @@ const SimulatedTransactionResponseValidator = jsonRpcResultAndContext(
  * @property {number} fee The fee charged for processing the transaction
  * @property {Array<number>} preBalances The balances of the transaction accounts before processing
  * @property {Array<number>} postBalances The balances of the transaction accounts after processing
+ * @property {Array<string>} logMessages An array of program log messages emitted during a transaction
  * @property {object|null} err The error result of transaction processing
  */
 type ConfirmedTransactionMeta = {
   fee: number,
   preBalances: Array<number>,
   postBalances: Array<number>,
+  logMessages?: Array<string>,
   err: TransactionError | null,
 };
 
@@ -1107,6 +1109,7 @@ const ConfirmedTransactionMetaResult = struct.union([
     fee: 'number',
     preBalances: struct.array(['number']),
     postBalances: struct.array(['number']),
+    logMessages: struct.union([struct.array(['string']), 'undefined']),
   }),
 ]);