Bug 17605: [STABLE] Add currency to orders generated by quotes

Bug 17605: [STABLE] Add currency to orders generated by quotes

Sets the vendors currency in the edi generated order
The currency used is agreed between vendor and library
and the value in the quote is optional

Edifact potentially allows the currency to be overwitten
by specifying another currency in the CUX segment but
we know currently of no supplier doing this

Signed-off-by: Alex Buckley <alexbuckley@catalyst.net.nz>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>