Extend Package data model to store additional information

Purpose/Overview:
Extend the package data model to enable storing additional information about packages
NB originally this included package identifiers, but this has been removed from this story while more analysis is done on requirements for handling identifiers where there are duplicates / errors etc.

Requirements
It should be possible to store the following additional information about packages in Agreements KB

• • zero to many package identifiers-

• a list of content types (content types will be ref data, a single package could have multiple content types, examples "Serials", "Monographs", "Databases"
• Package Lifecycle status: single value per package, ref data values:
  • Current
  • Retired
  • Expected
  • Deleted
• zero to many package description URLs
• zero to many alternate names
• Package availability scope: single value per package, ref data values:
  • Global
  • Consortial
  • Regional
  • Local
• Description
• Source data created (when the package was created in external data source)
• Source data updated (when the package was last updated in external data source)

Dev task breakdown
Add the following as straightforward fields:

• Description (long text)
• Source data created (store as instant, data type = timestamp)
• Source data updated (store as instant, data type = timestamp)
• Package lifecycle status (ref data)
• Package availability scope (ref data)

Repeatable fields (follow example pattern such as Agreements Alternate Name)

• Alternate names
• Package description URLs
• Content types

Ethan to discuss with Ian if the Identifiers re-use existing structure generalised to resources. Or copy the pattern and implement for packages