Now that we have an abstract partition table definition, we can use it to
generate org.osbuild.fstab stage options.
This is extremely nice because it removes magic contains.
Signed-off-by: Ondřej Budai <ondrej@budai.cz>
Using osbuild.QEMUAssemblerOptions to encode a partition table was weird.
This commit introduces a disk package that contains data types for defining
partition tables. Also, there's a handy function to convert the abstact
partition table to osbuild.QEMUAssemblerOptions.
Signed-off-by: Ondřej Budai <ondrej@budai.cz>
