feat(oas): identify required fields in responses - admin (#3278)

## Scope

Admin routes

## What

Add OAS `required` to response schemas.

## Why

Code generator can use the `required` property of a schema to mark fields as optional or not when generating TS types.

## Test

* Run `yarn build`
* Run `yarn openapi:generate`
* Run `yarn redocly preview-docs docs/api/admin/openapi.yaml --config=docs-util/redocly/config.yaml`
* Open the documentation preview URL in a browser (http://127.0.0.1:8080)
* Expect responses to have their fields declared as `required`

packages/medusa/src/api/routes/admin/draft-orders/index.ts

@@ -94,6 +94,8 @@ export const defaultAdminDraftOrdersFields: (keyof DraftOrder)[] = [
 /**
  * @schema AdminPostDraftOrdersDraftOrderRegisterPaymentRes
  * type: object
+ * required:
+ *   - order
  * properties:
  *   order:
  *     $ref: "#/components/schemas/Order"
@@ -105,6 +107,8 @@ export type AdminPostDraftOrdersDraftOrderRegisterPaymentRes = {
 /**
  * @schema AdminDraftOrdersRes
  * type: object
+ * required:
+ *   - draft_order
  * properties:
  *   draft_order:
  *     $ref: "#/components/schemas/DraftOrder"
@@ -116,6 +120,10 @@ export type AdminDraftOrdersRes = {
 /**
  * @schema AdminDraftOrdersDeleteRes
  * type: object
+ * required:
+ *   - id
+ *   - object
+ *   - deleted
  * properties:
  *   id:
  *     type: string
@@ -134,6 +142,11 @@ export type AdminDraftOrdersDeleteRes = DeleteResponse
 /**
  * @schema AdminDraftOrdersListRes
  * type: object
+ * required:
+ *   - draft_orders
+ *   - count
+ *   - offset
+ *   - limit
  * properties:
  *   draft_orders:
  *     type: array