Add aliases for running cxx-api scripts (facebook#56145)

Summary:
Pull Request resolved: facebook#56145

Add npm aliases for running python cxx-api snapshot generation script (build and validate):

```sh
python -m scripts.cxx-api.parser // cxx-api-build
python -m scripts.cxx-api.parser --check // cxx-api-validate
```

and also a js1 wrapper for buck equivalent.

Changelog:
[Internal]

Reviewed By: cortinico

Differential Revision: D97132752

fbshipit-source-id: e35d6d037ba3dad2a6b3294d0de9f5041847b33a

Author: coado

package.json

@@ -11,6 +11,8 @@
     "build-types": "node ./scripts/js-api/build-types",
     "clang-format": "clang-format -i --glob=*/**/*.{h,cpp,m,mm}",
     "clean": "node ./scripts/build/clean.js",
+    "cxx-api-build": "python -m scripts.cxx-api.parser",
+    "cxx-api-validate": "python -m scripts.cxx-api.parser --check",
     "flow-check": "flow check",
     "flow": "flow",
     "format-check": "prettier --list-different \"./**/*.{js,md,yml,ts,tsx}\"",