Return $metadata resource as odata + openapi spec

Returning odata and openapi specs in json format.
Specs are scoped to the request permissions.
Different users (roles) will receive different metadata endpoints
and resources.

Change-type: minor
Signed-off-by: Harald Fischer <harald@balena.io>

Author: fisehara

package.json

@@ -58,13 +58,15 @@
     "express-session": "^1.17.3",
     "lodash": "^4.17.21",
     "memoizee": "^0.4.15",
+    "odata-openapi": "^0.24.2",
     "pinejs-client-core": "^6.14.0",
     "randomstring": "^1.3.0",
     "typed-error": "^3.2.2"
   },
   "devDependencies": {
     "@balena/lint": "^7.2.4",
     "@faker-js/faker": "^8.3.1",
+    "@readme/openapi-parser": "^2.5.0",
     "@types/busboy": "^1.5.3",
     "@types/chai": "^4.3.11",
     "@types/chai-as-promised": "^7.1.8",