Config files and privileges

[id3v1669]

Requesting two features.

1. use config file in /etc/ox/ if user config files are not present
   Why: If ox is launched as a root process, ox tries to use the $HOME of the root user instead of the regular one. Editing files that need privileges requires at least two sets of configs.
2. handle privileged files when the ox is launched as an unprivileged process. Offer the user to save the file with sudo,doas,pkexec or any other present util when handling error KError::Io(ioerr), or during the save attempt, check if the file requires special permissions.

Implementing either of those features would make it a lot easier to edit privileged files.

[hced]

Added a related request: #216