Users: Changed name validation to min:1 instead of 2

Would cause scenarios where users could be created with 1 char, but then
fail to update due to validation differences.
Added test to cover.
For #5263

app/Users/Controllers/UserController.php

@@ -144,7 +144,7 @@ class UserController extends Controller
         $this->checkPermission('users-manage');
 
         $validated = $this->validate($request, [
-            'name'             => ['min:2', 'max:100'],
+            'name'             => ['min:1', 'max:100'],
             'email'            => ['min:2', 'email', 'unique:users,email,' . $id],
             'password'         => ['required_with:password_confirm', Password::default()],
             'password-confirm' => ['same:password', 'required_with:password'],