Expose getSize to transaction interface (#5983)

Signed-off-by: Gabriel-Trintinalia <gabriel.trintinalia@consensys.net>

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

@@ -219,4 +219,11 @@ public interface Transaction {
    * @return the encoded transaction as Bytes
    */
   Bytes encoded();
+
+  /**
+   * Returns the size in bytes of the encoded transaction.
+   *
+   * @return the size in bytes of the encoded transaction.
+   */
+  int getSize();
 }

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/core/Transaction.java

@@ -670,6 +670,7 @@ public class Transaction
    *
    * @return the size in bytes of the encoded transaction.
    */
+  @Override
   public int getSize() {
     if (size == -1) {
       memoizeHashAndSize();