Add JSDoc Type definitions

[Raynos]

There are a few changes here as well not related
to the type definitions

• cleanup benchmark / package.json
• Refactor static get type to use a Map and a function
  instead of storing the type on __type
• Make null checks explicit
• Use Reflect.get where applicable
• Cleanup do {} while loop.
• Handle case where stack is null or empty

TODO:

• Add tsdocstandard
• Add type-coverage