Add acquisition unit and internal note fields to GOBI configuration mapping

Current situation or problem: 

As more libraries implement the GOBI orders API, they may wish to customize their mapping files from GOBI to the FOLIO order/order line. After performing a comparison between the order/POL UI fields and https://github.com/folio-org/mod-gobi/blob/master/src/main/resources/mapping.json, I've determine the following fields are unaccounted for in the GOBI mapping:

Desired fields for mapping:

Acquisitions unit - should be able to specify a default for libraries with only a single unit

• Need 2 methods for acquisition unit mapping 1) Translation which looks up the correct acquisition unit based on the name taken from the xml file. 2) Look at Vendor and Account number and apply acquisition units from the field in FOLIO organization account field
• 
• Internal note (name is "Description" in POL schema)

Acceptance criteria:

A new method is created for the GOBI configuration for each field described above
 

Those fields in bold require the ability to perform a lookup to configured reference data.

These values have been requested by a live library. The desired value for internal note has been re-routed, but the library has to manually add an acquisitions unit to each GOBI order.