web3.js: add accounts support to simulateTransaction (#19590)

* feat: add accounts support to simulateTransaction

* feat: introduce test for simulateTransaction on Message objects

* feat: populate transaction from message defaults to no signatures

* fix: remove unused constant

* fix: small formatting error

* fix: eslint and prettier were fighting over ternary indentation

* fix: make simulated transaction result accounts nullable

web3.js/src/transaction.ts

@@ -666,7 +666,10 @@ export class Transaction {
   /**
    * Populate Transaction object from message and signatures
    */
-  static populate(message: Message, signatures: Array<string>): Transaction {
+  static populate(
+    message: Message,
+    signatures: Array<string> = [],
+  ): Transaction {
     const transaction = new Transaction();
     transaction.recentBlockhash = message.recentBlockhash;
     if (message.header.numRequiredSignatures > 0) {
@@ -688,9 +691,10 @@ export class Transaction {
         const pubkey = message.accountKeys[account];
         return {
           pubkey,
-          isSigner: transaction.signatures.some(
-            keyObj => keyObj.publicKey.toString() === pubkey.toString(),
-          ),
+          isSigner:
+            transaction.signatures.some(
+              keyObj => keyObj.publicKey.toString() === pubkey.toString(),
+            ) || message.isAccountSigner(account),
           isWritable: message.isAccountWritable(account),
         };
       });