Find missing chunks in filesystem

[dswd]

If for some reason chunks are missing from the bundle repository, try to find them in the real filesystem and store them in the repository again. Where to find the chunk in the filesystem can be obtained from the backup data, i.e. where the chunk is referenced contains the system and path of the file that chunk is in and even the exact position of the chunk in that file. When checking the integrity of a repository, this data can be obtained directly from the error location.