EVM processor Typescript: Better Object type merging with default provided type

[Yuripetusko]

fix this issue:

import {
  type Transaction as _Transaction,
} from '@subsquid/evm-processor';

export const processor = new EvmBatchProcessor()
  .addTransaction({
    type: [4],
  })
  .setFields({
    log: { transactionHash: true },
    transaction: {
      authorizationList: true,
    },
  });

export type Fields = EvmBatchProcessorFields<typeof processor>;
export type TransactionWithFields = _Transaction<Fields>;

fn(transaction: TransactionWithFields) {
 console.log(transaction.authorizationList) // Type is now correctly inferred
}

[Yuripetusko]

bump cc @eldargab (Sorry for tagging)