Clean up the directory of fightme_webapp/lib

[TaigaODonnell]

Probably should use MVC within our project for the frontend. We already have Models, we might as well go all the way.

• lib/
  ----/Models
  ----/Views
  ----/Controller
  --/main.dart

If we want to make it even cleaner, we can make it feature based architecture with mvc so it'll be like:

• lib/
  --/main.dart
  --/Core
  --/ProfileFeature
  --/Model
  --/View
  --/Controller
  --/SettingsFeature
  --/Model
  --/View
  --/Controller
  --/MessagingFeature
  --/Model
  --/View
  --/Controller

This can help us more with what each person does since in sprint 1, each of us didnt really know what to do (also dev environment problems). We can delegate a person to do a settings feature and another for leaderboards feature or something like that.