Add IsSynced function to the AWSResource interface (#67) (#69)

Follow up to aws-controllers-k8s/code-generator#247

Description of changes:
- Add `IsSynced` function to the `AWSResource` interface

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Issue #, if available:

Description of changes:

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Author: a-hilaly

mocks/pkg/types/aws_resource_manager.go

@@ -83,6 +83,8 @@ type AWSResourceManager interface {
 	// This method also adds/updates the ConditionTypeReferencesResolved for the
 	// AWSResource.
 	ResolveReferences(context.Context, client.Reader, AWSResource) (AWSResource, error)
+	// IsSynced returns true if a resource is synced.
+	IsSynced(context.Context, AWSResource) (bool, error)
 }
 
 // AWSResourceManagerFactory returns an AWSResourceManager that can be used to