Make POL vendor reference number and type repeatable, paired fields

Overview: Often there may be multiple vendor reference number for a single order line - example: a vendor title number and a vendor order transaction number. It would be helpful to make this a repeatable field. Also, there's room to spell out reference instead of abbreviating it, so spelling it out would make it more clear.

Acceptance criteria:

Given the user is working with POLs
When viewing or editing the POL
Then in the Vendor accordion the word "ref" in label us replaced with "reference"

Given the user is working with POLs
When viewing or editing the POL
Then vendor reference number and vendor reference type are a repeatable field set
AND display as table in view pane

(This last scenario may be a backend story? And may need migration script from the former vendor reference type terms?)
Given the user is working with POLs
When viewing or editing the POL
Then the vendor reference types select list includes the following fields

• Vendor continuation reference number - (replaces Library's continuation order number and Supplier's continuation order)
• Vendor internal number - (replaces Internal vendor number)
• Vendor order reference number - (replaces Supplier's unique order line reference number)
• Vendor subscription reference number - (replaces Agent's unique subscription reference number)
• Vendor title number - (new - does not replace anything)