Move test_snapshot_list_* tests to new file

test_snapshot_list_param_* tests require two volume snapshots.
Moving all *_list_* tests to new file will repair
gate-tempest-dsvm-full-bdd-nv job.

Closes-bug: #1593278

Change-Id: I1cff2bd62a40659f291ec7b78dbe080686149e34
2 files changed