Domain.clone() returns a new Domain object (#286)

## 📝 Description

`Domain.clone()` returns a new `Domain` object.

## ✔️ How to Test

`pytest test`

Ticket: TPT-2019

Author: ezilber-akamai-zz

linode_api4/objects/domain.py

@@ -128,10 +128,12 @@ def clone(self, domain: str):
         """
         params = {"domain": domain}
 
-        self._client.post(
+        result = self._client.post(
             "{}/clone".format(self.api_endpoint), model=self, data=params
         )
 
+        return Domain(self, result["id"], result)
+
     def domain_import(self, domain, remote_nameserver):
         """
         Imports a domain zone from a remote nameserver. Your nameserver must

test/fixtures/domains_12345_clone.json

@@ -4,7 +4,7 @@
     "domain": "example.org",
     "expire_sec": 300,
     "group": null,
-    "id": 1234,
+    "id": 12345,
     "master_ips": [],
     "refresh_sec": 300,
     "retry_sec": 300,

test/objects/domain_test.py

@@ -35,9 +35,10 @@ def test_clone(self):
         domain = Domain(self.client, 12345)
 
         with self.mock_post("/domains/12345/clone") as m:
-            domain.clone("example.org")
+            clone = domain.clone("example.org")
             self.assertEqual(m.call_url, "/domains/12345/clone")
             self.assertEqual(m.call_data["domain"], "example.org")
+            self.assertEqual(clone.id, 12345)
 
     def test_import(self):
         domain = Domain(self.client, 12345)