Reorgranised blade view files to form a convention

- Primarily moved and re-organised view files.
- Included readme within views to document the convention.
- Fixed some issues with page field select list in previous commit.
- Tweaked some route names while going through.
- Split some views out further.

Closes #2805

resources/views/mfa/backup-codes-generate.blade.php

@@ -1,4 +1,4 @@
-@extends('simple-layout')
+@extends('layouts.simple')
 
 @section('body')