Use /* notation for subdir uncompression and allow subdir uncompression if file is archive
This is needed for the KRunner store because plugins like https://store.kde.org/p/1414906/ are not contained in a subdir.
And when using the subdir compression in the knsrc file we get the first file of the list of extracted files passed to the script, this makes it pretty much useless. Also the /* syntax is used when uncompressing archives and is already handled when calling a script with such a path.
It also makes logically sense to persist the entire dir instead of all the individual files.
And the subdir-archive setting is needed, because we have the case we we want to uncompress it in a subdir if it is an archive, but otherwise just move the file. If we use the subdir setting KNS would exit with an error if it is not an archive, but for instance a deb package.