Add TransferOutput model (#299)

* Feat: added additional transaction fields (sequenceNumber + time)

* Feat: added getters + adjusted new constructor use

* Feat: added TransferOutput model

* Docs: added some doc comments

* Docs: updated docs comments

* Refactor: refactored some code

* Docs: added comments for the bytes methods of marshalUtil

* Docs: adjusted some docs

* Feat: refactored some code