Fink LSST schema is not correct

The current Fink LSST schema is not correct:
- `xm.spicy_CLASS` does not exist anymore
- `clf.slsn_score` does not exist
- `fink_broker_version` is wrongly written `fink.broker_version`
- `fink_science_version` is wrongly written `fink.science_version`
- `lsst_schema_version` is wrongly written `lsst.schema_version`

