Improve withdrawals processing performance (hyperledger#5026)

* Improve withdrawals processing performance
* Add a changelog entry
* refactoring + remove the changelog entry as we have not change logs for the withdrawals

Signed-off-by: Ameziane H <ameziane.hamlat@consensys.net>

datatypes/src/main/java/org/hyperledger/besu/datatypes/GWei.java

@@ -34,6 +34,9 @@ public final class GWei extends BaseUInt64Value<GWei> implements Quantity {
   /** The constant MAX_GWEI. */
   public static final GWei MAX_GWEI = of(UInt64.MAX_VALUE);
 
+  /** The constant GWEI_TO_WEI_MULTIPLIER. */
+  private static final BigInteger GWEI_TO_WEI_MULTIPLIER = BigInteger.valueOf(1_000_000_000L);
+
   /**
    * Instantiates a new GWei.
    *
@@ -111,7 +114,7 @@ public static GWei fromHexString(final String str) {
    * @return Wei
    */
   public Wei getAsWei() {
-    return Wei.of(getAsBigInteger().multiply(BigInteger.TEN.pow(9)));
+    return Wei.of(getAsBigInteger().multiply(GWEI_TO_WEI_MULTIPLIER));
   }
 
   @Override

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/bonsai/BonsaiWorldStateUpdater.java

@@ -284,7 +284,8 @@ public void commit() {
                             new BonsaiValue<>(wrappedWorldView().getCode(addr).orElse(null), null));
                 pendingCode.setUpdated(updatedAccount.getCode());
               }
-
+              // This is especially to avoid unnecessary computation for withdrawals
+              if (updatedAccount.getUpdatedStorage().isEmpty()) return;
               final StorageConsumingMap<BonsaiValue<UInt256>> pendingStorageUpdates =
                   storageToUpdate.computeIfAbsent(
                       updatedAddress,