Add UserGroup to chill (import from branch ticket-app-master)

Import the UserGrou feature from ticket-app-master branch. This includes:

- import all the entities and migrations, modification of typescript types, templating, and so on;
- apply some verification and formatting rules, like:
  - reformat file on chill.api.specs.yaml (MainBundle)
  - reformat file on types.ts (Main Bundle)

Migrations kept the same filename.

src/Bundle/ChillMainBundle/config/services/templating.yaml

@@ -56,6 +56,10 @@ services:
 
     Chill\MainBundle\Templating\Entity\UserRender: ~
 
+    Chill\MainBundle\Templating\Entity\UserGroupRender: ~
+    Chill\MainBundle\Templating\Entity\UserGroupRenderInterface:
+        alias: Chill\MainBundle\Templating\Entity\UserGroupRender
+
     Chill\MainBundle\Templating\Listing\:
         resource: './../../Templating/Listing'