Changed the way in which volumes are iconized and/or saved, which no longer...

Changed the way in which volumes are iconized and/or saved, which no longer worked in Qt6 and is anyhow better:

1. To iconize, use ctrl+shift+click
2. To save as a file, use alt+click

enabled an automatic merge when the pipeline for fd53f355 succeeds

mentioned in commit a62e94ca

merged