message: feat(transactions): more exports
diff: -export { StacksTransaction } from './transaction';
  +export { StacksTransaction, deserializeTransaction } from './transaction';
  +
  +export { BufferReader } from './bufferReader';
  export {
  Authorization,
  StandardAuthorization,
  SponsoredAuthorization,
  SpendingCondition,
  + MessageSignature,
  + createMessageSignature,
  + emptyMessageSignature,
  + isSingleSig,
  } from './authorization';
  export {
  