Removed role 'name' field from database

The 'name' field was really redundant and caused confusion in the
codebase, since the 'Display' name is often used and we have a
'system_name' for the admin and public role.

This fixes #2032, Where external auth group matching has confusing
behaviour as matching was done against the display_name, if no
external_auth field is set, but only roles with a match 'name' field
would be considered.

This also fixes and error where the role users migration, on role
delete, would not actually fire due to mis-matching http body keys.
Looks like this has been an issue from the start. Added some testing to
cover. Fixes #2211.

Also converted phpdoc to typehints in many areas of the reviewed code
during the above.

app/Http/Controllers/UserController.php

@@ -66,8 +66,8 @@ class UserController extends Controller
     {
         $this->checkPermission('users-manage');
         $validationRules = [
-            'name'             => 'required',
-            'email'            => 'required|email|unique:users,email'
+            'name'  => 'required',
+            'email' => 'required|email|unique:users,email'
         ];
 
         $authMethod = config('auth.method');