Bugs with the condition keywords `within` and `not_within`

If I read it correctly, the current implementation for the within and not_within selections don't work:

https://gitlab.cern.ch/gnn4itkteam/acorn/-/blob/dev/acorn/utils/mapping_utils.py?ref_type=heads#L33-37

We should change:

condition_val[0] -> condition_val[1][0]

condition_val[1] -> condition_val[1][1]