Renewal/subscription PO schema changes

Overview

• Rename the "renewal" field to "ongoing" in purchaseOrder/CompositePurchaseOrder schemas
• Rename the "renewal" schema to "ongoing"
• Remove "cycle" from the ongoing schema
• Remove the default value from "manualRenewal" in the ongoing schema - in some cases it doesn't makes sense to have this field present so we don't want a default value.
• Add a "isSubscription" field to the ongoing schema.
  • boolean
  • default: false
• Change description of "renewalDate" to: "The date this Ongoing PO's order lines were renewed"

Data Migration Considerations

• need to add new field w/ default value (false)
• for existing records with renewal information, they must have a renewalInterval set - dennisbridges what's a reasonable value to use in this case? 365 days
  • this isn't required in the schemas but it is conditionally required (if orderType=ongoing && subscription=true) - see MODORDERS-351
• some fields will need to be renamed if present in existing records

Acceptance Criteria

• schemas and examples are updated
• sample data is updated
• data migration scripts are implemented