[feat] add Export as OFX in transfer_history_menu

tikka/adapters/network/indexer/transfers.py

tikka/domains/application.py

tikka/domains/indexers.py

tikka/domains/nodes.py

tikka/domains/transfers.py

tikka/interfaces/adapters/network/indexer/transfers.py

tikka/slots/pyqt/entities/constants.py

tikka/slots/pyqt/resources/gui/windows/transfers_export.ui

tikka/slots/pyqt/widgets/transfer_history_menu.py

tikka/slots/pyqt/windows/transfers_export.py