Vendor Item Import - Add support for new fields

As an admin I want to support more fields in the Vendor Item Import so that I can use the new Manage Vendor Item Assignment module in place of the Vendor Entity Item import

Notes:

• There will be some vendors who use both the Vendor Item and Vendor Entity Item Imports
• There will be other vendors who will only use the Vendor Item Import, and the Vendor Entity Items will be created/maintained via the Manage Vendor Item Assignment module
• Confluence Page: https://hotschedules.atlassian.net/wiki/spaces/RBCD/pages/194150488/CFA+Version+of+Vendor+Item+Import+Template?atlOrigin=eyJpIjoiZjA2OWE3OWNjZDlhNGZlNTliNGQxYTI2M2MxOTg1YmYiLCJwIjoiYyJ9
• Sample Vendor Item file (From PROD)
• VENDORITEM_20181109_0334.csv

Acceptance Criteria

• ALL NEW fields must be optional, if they are not provided, there should be no default action (the import will continue to be used in it's current form by some vendors)
• New fields/additions, listed below:
• Purchase Unit (Update)
  • Add directives: {UpdateVendorEntityItem} & {DefaultToReportingUnit}
    • UpdateVendorEntityItem - when included update any vendor entity items
    • DefaultToReportingUnit -
    • See notes in blue in on the Confluence page
• PerformStockCount (new)
  • Add directive: {UpdateVendorEntityItem}
• StockTakeInner (new)
  • Add directive: {UpdateVendorEntityItem}

• SetCostToLastPurchasePrice (new)
  • Add directive: {UpdateVendorEntityItem}

• ReplacedVendorItemCode (new)
  • Add directive: {UpdateVendorEntityItem}

• Ensure that when Vendor Entity Items are created, manually, using the new Manage Vendor Item Assignment module, any default values are correctly populated
  • In other words, if these values need to be persisted somewhere, as a default set of values, we should also do that (it may not be necessary, but just trying to cover bases)