Create 1 load Class instead of 3 bootstrapper

[beumerr]

Currently, there are 3 bootstrappers:

1. src/index.php - used to compile the theme
2. src/admin/index.php - used to compile the admin panel
3. src/admin/inc/qc-load-xml.php - used to compile an XML requests

It would be a better solution to create 1 load Class which loads relevant data based on constructor attributes. Now there is a lot of maintaining to do when the start till end process changes a bit.