FS: port q-s-m tests to new infrastructure

Port the [existing q-s-m tests](https://github.com/input-output-hk/ouroboros-network/blob/master/ouroboros-consensus-test/test-storage/Test/Ouroboros/Storage/FS/StateMachine.hs) to use the high-level interface described in https://github.com/advancedtelematic/quickcheck-state-machine/pull/355. See http://www.well-typed.com/blog/2019/01/qsm-in-depth/ for more details. As the FS tests have references (file handles and paths), `Test.StateMachine.Lockstep.NAry` has to be used instead of `Test.StateMachine.Lockstep.Simple`.

This interface will likely need some changes before we can adopt it. It might be a good idea to make a local copy of that q-s-m infrastructure so that we can quickly modify it instead of having to submit PRs against the upstream repo and wait for them to get merged.

Related: input-output-hk/ouroboros-consensus#620.