feat: convert recursion to iteration

[buehler]

Convert the recursive parsing process into an iterative one (for better memory consumption and performance)

[shobhitg]

Which part of the code is recursive that needs to be iterative?

[buehler]

It's actually this function:
https://github.com/buehler/node-typescript-parser/blob/develop/src/TypescriptParser.ts#L154

I thought of a worker / creator setup in which a function can create working tasks that are later used by workers to parse the symbols. And when they encounter next parts that should be parsed, they can create a task. Or maybe with RXJS and an observable.