Discounts GraphQL Admin API feature update

We've added some new features to Discounts on the GraphQL Admin API, including:

• Usage counts for automatic discounts.
• New ways to search through discounts.
• Speed up the management of discounts with bulk mutations!

We've also deprecated the type filter parameter on CodeDiscountQuery. Use discount_type instead.

For the full list of changes, see the 2020-10 release notes.