feat: add one to one relationship for embedding

BREAKING CHANGE: For the cases where one to one relationships are
detected, json objects will be returned instead of json arrays of length
1.

If you wish to override this behavior, you can use computed
relationships to return arrays again.

test/spec/Feature/Query/UpdateSpec.hs

@@ -374,6 +374,34 @@ spec = do
           matchHeaders = [matchContentTypeJson]
         }
 
+    it "embeds an O2O relationship after update" $ do
+      request methodPatch "/students?id=eq.1&select=name,students_info(address)"
+              [("Prefer", "return=representation")]
+        [json|{"name": "Johnny Doe"}|]
+        `shouldRespondWith`
+        [json|[
+          {
+            "name": "Johnny Doe",
+            "students_info":{"address":"Street 1"}
+          }
+        ]|]
+        { matchStatus  = 200,
+          matchHeaders = [matchContentTypeJson]
+        }
+      request methodPatch "/students_info?id=eq.1&select=address,students(name)"
+              [("Prefer", "return=representation")]
+        [json|{"address": "New Street 1"}|]
+        `shouldRespondWith`
+        [json|[
+          {
+            "address": "New Street 1",
+            "students":{"name": "John Doe"}
+          }
+        ]|]
+        { matchStatus  = 200,
+          matchHeaders = [matchContentTypeJson]
+        }
+
   context "table with limited privileges" $ do
     it "succeeds updating row and gives a 204 when using return=minimal" $
       request methodPatch "/app_users?id=eq.1"