Add testQueryBeforeAfterUpdateForSubobjectToLooseReference

Test is in response to https://github.com/SemanticMediaWiki/SemanticMediaWiki/pull/378#discussion_r14574081
> It's nice you've clearly labelled the different parts

It is a longer test so this is more for people who are not so familiar with the test code.

> Though why not do so by splitting this up in well named methods?

Normally I would say yes when having one long test that is bound to its own class where those methods are easily associated with the class and the single test.

I really wonder if doing below would help that much when trying to follow the test because now you have to look for `createSemanticDataWithSingleSubobjectPropertyValueAnnotation` where currently you just follow down the method to see what's going on.

The dilemma here is visibility vs. shortness.

```php
	list( $semanticData, $property, $dataItem ) = $this->createSemanticDataWithSingleSubobjectPropertyValueAnnotation(
		__METHOD__,
		'SubobjectToTestReferenceAfterUpdate',
		9999
	);

	$this->store->doSparqlDataUpdate( $semanticData );

	$query = $this->buildQueryForSomePropertyValueDescription( $property, $dataItem );

	$this->assertSame(
		1,
		$this->store->getQueryResult( $query )->getCount()
	);

	...
```