Clean up sys-aksql in yaml tests

Delete suppression statements with that as the property as 1) it was renamed quite a while ago 2) they pass just fine now.

The test-yaml-unittest-ak-fts.yaml and test-yaml-unittest-ak-it.yaml tests were doing funny things to wrap all-yaml-unittest but always disabled. Delete the former and rename the latter so it is ran on its own

Also rename the select-engine tag to fdb-sql (corresponding AAS branch) for consistency.