Resource type handler_update fails to delete the right model version

The [updated_resource in handler_update](https://github.com/aws-cloudformation/cloudformation-cli/blob/master/src/rpdk/core/contract/suite/resource/handler_update.py#L44) resource type test suite is wrongly deleting the created model in its `finally` section instead of the potentially updated model.

My resource type is maintaining a Version field on the server with optimistic locking to avoid accidental overwrite of the resource. Upon a successful update, the version is auto-incremented and the new version is returned to the client. The client specifies the version in the `If-Match` header of the HTTP request, and the server allows the mutation only if the version stored is the same.

In the following function:

```python
def updated_resource(resource_client):
create_request = input_model = resource_client.generate_create_example()
model = {}
try:
_status, response, _error = resource_client.call_and_assert(
Action.CREATE, OperationStatus.SUCCESS, create_request
)
created_model = model = response["resourceModel"]
test_input_equals_output(resource_client, input_model, created_model)

update_request = resource_client.generate_update_example(created_model)

_status, response, _error = resource_client.call_and_assert(
Action.UPDATE, OperationStatus.SUCCESS, update_request, created_model
)
updated_model = response["resourceModel"]
test_input_equals_output(resource_client, update_request, updated_model)

# flake8: noqa: B950
# pylint: disable=C0301
yield create_request, created_model, update_request, updated_model, update_request
finally:
resource_client.call_and_assert(Action.DELETE, OperationStatus.SUCCESS, model)
```

The following call to update:
```python
_status, response, _error = resource_client.call_and_assert(
Action.UPDATE, OperationStatus.SUCCESS, update_request, created_model
)
updated_model = response["resourceModel"]
```
increments the resource version but the delete is made on the original `model`, which in my case, has the previous version, and thus fails:
```python
finally:
resource_client.call_and_assert(Action.DELETE, OperationStatus.SUCCESS, model)
```

A potential fix, is to update the `model` upon successful update:
```python
_status, response, _error = resource_client.call_and_assert(
Action.UPDATE, OperationStatus.SUCCESS, update_request, created_model
)
model = updated_model = response["resourceModel"]
```

When trying to delete the resource in the `finally` section now, the right `model` is provided