feat(medusa): Convert SwapService to TypeScript (#2000)

**What**
- refactor swap service to typescript
- reimplement legacy methods
- use enums instead of magic strings

RESOLVES CORE-396

Co-authored-by: Oliver Windall Juhl <59018053+olivermrbl@users.noreply.github.com>

packages/medusa/src/models/swap.ts

@@ -25,6 +25,7 @@ export enum SwapFulfillmentStatus {
   NOT_FULFILLED = "not_fulfilled",
   FULFILLED = "fulfilled",
   SHIPPED = "shipped",
+  PARTIALLY_SHIPPED = "partially_shipped",
   CANCELED = "canceled",
   REQUIRES_ACTION = "requires_action",
 }
@@ -190,7 +191,7 @@ export class Swap extends SoftDeletableEntity {
  *     description: Available if the relation `shipping_address` is expanded.
  *     $ref: "#/components/schemas/address"
  *   shipping_methods:
- *     description: The Shipping Methods used to fulfill the addtional items purchased. Available if the relation `shipping_methods` is expanded.
+ *     description: The Shipping Methods used to fulfill the additional items purchased. Available if the relation `shipping_methods` is expanded.
  *     type: array
  *     items:
  *       $ref: "#/components/schemas/shipping_method"