rename db column 'mask_level' into 'mask_group_id'

See #144

In this solution, the column `mask_level` is renamed into `mask_group_id` to reflect the fact that it stores B3 group id.

Additionally:
- B3 version is bumped to `1.10.1` so we can apply a new upgrade SQL script over existing `1.10.0` compatible databases.
- the `maskLevel` property is removed from the `Client` class in favor of `maskGroup` which makes more sense in plugin code.
- and reflect that change to a hack found in the iourt4x parsers