Bug 24158: Convert actual cost in an other currency when receiving

Bug 24158: Convert actual cost in an other currency when receiving

This patch adds a currency dropdown list to the Actual cost field when
receiving items in the acquisition module.
The idea is to let the librarian entered a price in a foreign currency
that will automatically be converted in the local currency ('active').
This converted value will be use as the actual cost once the form is
submitted.

Test plan:
- Create several currencies with different rates
- Create an order, close the basket and receive
- On the receipt page you will notice a new "change currency" checkbox
right close to the 'Actual cost' input.
- Check it
=> The 'Actual cost' input is readonly and a new line appears at the
bottom.
- Enter a number and select a currency
=> The 'Actual cost' input is automatically filled with the converted
value
- Save
=> The converted Actual cost has been inserted in the database.

Sponsored-by: Athlone Institute of Technology
Signed-off-by: Devinim <nazli@devinim.com.tr>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>