Name-preserving `Group Datasets` filter
- open several files (doesn't matter which) or create mutiple sources.
- next group all of them using "Group Datasets".
While now you can apply filters to the group collectively, the names used for each of the source in the pipeline browser are not preserved in the multiblock structure and hence one cannot effectively use the Multblock Inspector to control block visibilities etc.
We need a "Group Dataset" mode where the names for inputs are preserved.