Add ARCHIVE_READDISK_NO_SPARSE to suppress reading sparse file info

Add ARCHIVE_READDISK_NO_SPARSE to suppress reading sparse file info

Sparse file information depends on the file system and can therefore be a
source of unreproducibility for the generated archives, e.g. if the same
content is compressed on a file system with and without sparse file support.
Add an option to suppress reading this information from disk entirely.