Previously, ResetMocksTestExecutionListener used getBean(name) to
retrieve each instantiated singleton. When the instantiated singleton
was a factory bean, this would cause getObject on the factory bean to
be called. If the factory bean was unable to produce its object, for
example due to test slicing excluding something, an exception would
be thrown.

The previous commit updated ResetMocksTestsExecutionListener to
use getSingleton(name) rather than getBean(name).  This will retrieve
the factory bean itself rather than causing the factory bean to
attempt to create an object. This commit updates the tests to verify
the new behaviour.

Closes gh-7270