Add distinct, order_by and all method signatures for _ValuesQuerySet (#657)

tests/typecheck/managers/querysets/test_values_list.yml

@@ -26,6 +26,25 @@
                     name = models.CharField(max_length=100)
                     age = models.IntegerField()
 
+-   case: values_list_supports_queryset_methods
+    main: |
+        from myapp.models import MyUser
+        query = MyUser.objects.values_list('name')
+        reveal_type(query.order_by("name").get())  # N: Revealed type is "Tuple[builtins.str]"
+        reveal_type(query.distinct("name").get()) # N: Revealed type is "Tuple[builtins.str]"
+        reveal_type(query.distinct().get()) # N: Revealed type is "Tuple[builtins.str]"
+        reveal_type(query.all().get()) # N: Revealed type is "Tuple[builtins.str]"
+    installed_apps:
+        - myapp
+    files:
+        -   path: myapp/__init__.py
+        -   path: myapp/models.py
+            content: |
+                from django.db import models
+                class MyUser(models.Model):
+                    name = models.CharField(max_length=100)
+                    age = models.IntegerField()
+
 -   case: values_list_related_model_fields
     main: |
         from myapp.models import Post, Blog