Request reconcile using patch instead of update

This should prevent the generation of the object getting bumped, as
observed on a GKE K8s 1.18 cluster using the  logic before this commit.

We only want to generation to increase when there are actual changes to
the `spec` of a resource, as some controllers use the `generation`
value to make assumptions about what they should do during a
reconciliation.

Signed-off-by: Hidde Beydals <hello@hidde.co>

cmd/flux/object.go

@@ -39,6 +39,13 @@ type adapter interface {
 	asClientObject() client.Object
 }
 
+// copyable is an interface for a wrapper or alias from which we can
+// get a deep copied client.Object, required when you e.g. want to
+// calculate a patch.
+type copyable interface {
+	deepCopyClientObject() client.Object
+}
+
 // listAdapater is the analogue to adapter, but for lists; the
 // controller runtime distinguishes between methods dealing with
 // objects and lists.