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/ChillPersonBundle/Resources/public/chill/scss/badge.scss

@@ -3,8 +3,10 @@
 */
 
 span.badge-user,
+span.badge-user-group,
 span.badge-person,
 span.badge-thirdparty {
+    margin: 0.2rem 0.1rem;
     display: inline-block;
     padding: 0 0.5em !important;
     background-color: $white;
@@ -18,6 +20,11 @@ span.badge-thirdparty {
     }
 }
 
+span.badge-user-group {
+    font-weight: 600;
+    border-width: 0px;
+}
+
 span.badge-user {
     border-bottom-width: 1px;
     &.system {