Test QueryRunner#run :filter option
Test QueryRunner#run :filter option

QueryRunner.run can have the output limited by a filter expression.

This adds tests that ensure that a 'previously multiple record' query
is subsequently reduced down to a single known record via a filter on the
(unique) href field.

UKHomeOffice/vcloud-core,gds-operations/vcloud-core,UKHomeOffice/vcloud-core,gds-operations/vcloud-core