feat: restructure project for easier management of extensions, initial I/O operations

[Im-Beast]

This PR restructures project so that extensions can be reused, there's no need to redefine them multiple times.

Project structure:

• /bueno - bueno_runtime package, main stuff
• /ext - bueno_ext package, things related to extensions, exposes extensions module which contains all extensions that are declared by ext.

Bueno. api /ext structure:

• /ext/{api_name}/mod.js - JavaScript module where globalThis is modified in any way
• /ext/{api_name}/{whatever}.js - modules imported by mod.js, they mustn't modify globalThis in any way

This PR also adds support for these API's (#6):

• Bueno.io
  • read – read from resource id into given Uint8Array
  • readSync – sync version of io.read
  • write – async write to resource id using Uint8Array
  • writeSync – sync version of io.write
  • stdin – interface for working with standard input
  • stdout – interface for working with standard output
  • stderr – interface for working with standard error output

Std{in,out,err} classes are not finalized, currently they only have write/data/close methods.