The original name PxarExcludePattern makes no sense anymore as the patterns are
also used to match filenames during restore of the archive.
Therefore, exclude_pattern.rs is moved to match_pattern.rs and PxarExcludePattern
rename to MatchPattern.
Further, since it makes more sense the MatchTypes are now declared as None,
Positive, Negative, PartialPositive or PartialNegative, as this makes more sense
and seems more readable.
Positive matches are those without '!' prefix, Negatives with '!' prefix.
This makes also the filename matching in the encoder/decoder more intuitive and
the logic was adapted accordingly.
Signed-off-by: Christian Ebner <c.ebner@proxmox.com>