Repeated execution of triple pattern queries which should be prevented by the cache-db

[Aklakan]

Running LSQv2 on LGD revealed repeated attempts to execute SELECT * { ?s ?p ?o } queries; conceptually this should not happen as within a single benchmark run each normalized query string should be attempted to execute only once.

[Aklakan]

The reason was that queries derived from triple patterns of primary queries were treated as 'second-class citizens' which meant they did not go through the caching system.
There have been revisions in the LSQ code base such that both primary and secondary queries use the same cache system.
Most likely this issues is fixed, but a test case should be added for verification.