Refactor: Implement chainable AST / functional AST handlers

[barelyhuman]

The current implementation generates the AST on every needed point instead of using the existing one if no modifications are made.

All code regarding this can be found in
lib/ast-helpers.js
lib/jsx-helpers.js

The needed change is to have a chainable contructor that allows doing the same manipulations as already in the functions but instead using a single ast as needed.

The other approach is to be functional and pass the ast around in the functions as a parameter, though that increases the amount of memory transferred around so the chain approach is preferrable.

Post the modification,
Test the application by visiting the web url : http://localhost:3000 or whatever port you have it on and then check if both the default code and the example code run (Click the View Example button ) properly without any issues.

[barelyhuman]

407c247

Initial changes done,
can be optimized even more to reduce the transform time from the API for larger code snippets.