This PR adds detection of exclusion attributes on files and folders. If a file or folder has an exclusion extended attribute, the file or folder is excluded from the backup.
The option `--disable-backup-exclusion-xattr` can be used to revert to the previous behavior where the xattrs were not checked.
This has the biggest impact on MacOS where it will not perform like other backup software and avoid files that are marked as excluded from backup.
This fixes#6393
Kenneth Skovhede