Extract Form Controller as a Separate Package

[ChakshuGautam]

Description

Currently, the form-controller is part of Enketo client and can live outside of it as a package. Keeping it outside of Enketo will allow for

1. Decoupling would allow for easier upgrades to Enketo.
2. Enable it to be written in TypeScript. Faster and safer development lifecycle.
3. Ability to add tests for features without Enketo.

Things to implement

• Extract form-controller as a separate package and import into enketo
• Use Typescript to refactor the code (index.js -> index.ts)
• Make the build command, automatically push the package to the NPM registry
• Use babel and browserify to convert the nodeJS APIs to browser based APIs
• Enable easy setup of the form-controller package using the npm install command.

[Ansh-Sarkar]

Current status on the development of the package can be seen at : Ansh-Sarkar/form-controller