Datalab storage configuration in regards to CSI-FUSE

[achtsnits]

Goals

• Enable mounting object storage (via CSI driver with FUSE) also in Terminal and VSCode Server pods, not only in the File Browser.
• Ensure object storage mounts are read-only by default (as intended primarily for browsing), but allow configuration for read/write access — with appropriate user acknowledgment due to potential large file upload/download implications.