Re-introduce strict volume check in mastercontainer with nc33

[szaimen]

• Add a link to https://github.com/nextcloud/all-in-one?tab=readme-ov-file#how-to-store-the-filesinstallation-on-a-separate-drive
• Re-introduce mastercontainer: make check for correct volume name more strict #7485
• Revert Revert "mastercontainer: make check for correct volume name more strict" #7585