refactor: use prepare npm hook for ngc compilation and metadata cleanup

- metadata will now be shipped with the package

Author: sis0k0

nativescript-angular/bin/remove-polyfills-metadata.js

@@ -0,0 +1,5 @@
+const { unlinkSync } = require("fs");
+
+unlinkSync("./polyfills/console.metadata.json");
+unlinkSync("./polyfills/array.metadata.json");
+

nativescript-angular/package.json

@@ -33,7 +33,7 @@
     "postinstall": "node postinstall.js",
     "tsc": "tsc -p tsconfig.json",
     "ngc": "ngc -p tsconfig.json",
-    "prepublish": "npm run tsc && npm run ngc"
+    "prepare": "npm run ngc && node ./bin/remove-polyfills-metadata.js"
   },
   "bin": {
     "update-app-ng-deps": "./bin/update-app-ng-deps"