9478 link peers to GraphQL (#10574)

* 9468 add link_peer to GraphQL

* 9478 add class_type

* 9478 fix tests

* 9478 fix tests

* 9478 fix tests

netbox/dcim/graphql/gfk_mixins.py

@@ -0,0 +1,59 @@
+import graphene
+from circuits.graphql.types import CircuitTerminationType
+from circuits.models import CircuitTermination
+from dcim.graphql.types import (
+    ConsolePortType,
+    ConsoleServerPortType,
+    FrontPortType,
+    InterfaceType,
+    PowerFeedType,
+    PowerOutletType,
+    PowerPortType,
+    RearPortType,
+)
+from dcim.models import (
+    ConsolePort,
+    ConsoleServerPort,
+    FrontPort,
+    Interface,
+    PowerFeed,
+    PowerOutlet,
+    PowerPort,
+    RearPort,
+)
+
+
+class LinkPeerType(graphene.Union):
+    class Meta:
+        types = (
+            CircuitTerminationType,
+            ConsolePortType,
+            ConsoleServerPortType,
+            FrontPortType,
+            InterfaceType,
+            PowerFeedType,
+            PowerOutletType,
+            PowerPortType,
+            RearPortType,
+        )
+
+    @classmethod
+    def resolve_type(cls, instance, info):
+        if type(instance) == CircuitTermination:
+            return CircuitTerminationType
+        if type(instance) == ConsolePortType:
+            return ConsolePortType
+        if type(instance) == ConsoleServerPort:
+            return ConsoleServerPortType
+        if type(instance) == FrontPort:
+            return FrontPortType
+        if type(instance) == Interface:
+            return InterfaceType
+        if type(instance) == PowerFeed:
+            return PowerFeedType
+        if type(instance) == PowerOutlet:
+            return PowerOutletType
+        if type(instance) == PowerPort:
+            return PowerPortType
+        if type(instance) == RearPort:
+            return RearPortType