Add a new module containing key-related functions and schemata from all
over, code moved is not changed as much as possible.
Requires adapting some 'use' statements across proxmox-backup-client and
putting the XDG helpers quite cozily into proxmox_client_tools/mod.rs
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
to avoid confusing messages about using encryption keys when restoring
plaintext backups, or about loading master keys when they are not
actually used for the current operation.
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>