[Feature request] Ability to merge different datasets

[JoQCcoz]

It would be nice to have the ability to merge particles or imports during the projects workflow.

For example, we have 2 datasets of lamellaes from the same types samples collected at different times. We cannot merge the data before import since they have different gain references.

[abartesaghi]

For merging datasets, there is a related issue on the main discussions page.