Compare agreement content

Enable the comparison of agreements in terms of :

• Comparing the content (resources) in an agreement and how they differ in terms of specific content (eg books/journals encompassed by the agreement) and coverage of those resources

This is a slightly broader requirement than https://issues.folio.org/browse/UXPROD-1474 because Agreements can contain multiple Packages and individual Titles

It is expected that it will be possible to compare:

• draft/future agreements (created in advance of ordering or trialling a resource)
• trial agreements
• current agreements
• past agreements