VersionedGraphTestSuite compatibility with transactional versioned graph.

Since this test suite contains the basic tests of a versioned graph
it should be compatible and behaves equaly when used with a transactional
/ non-transactional versioned graph implementation.

The same behavior is basically achieved by committing every single change in the
tests when running with a transactional versioned graph.
Enabled basic graph tests execution in transactional long identifier graph tests.