feat: Typescript for API layer (#817)

Co-authored-by: Philip Korsholm <88927411+pKorsholm@users.noreply.github.com>
Co-authored-by: Zakaria El Asri <33696020+zakariaelas@users.noreply.github.com>
Co-authored-by: Kasper Fabricius Kristensen <45367945+kasperkristensen@users.noreply.github.com>
Co-authored-by: Philip Korsholm <philip.korsholm@hotmail.com>
Co-authored-by: Sebastian Rindom <seb@medusa-commerce.com>

packages/medusa-interfaces/package.json

@@ -38,4 +38,4 @@
     "medusa-core-utils": "^1.1.26"
   },
   "gitHead": "41a5425405aea5045a26def95c0dc00cf4a5a44d"
-}
+}