This is a step towards making migration unit-testable. This step
reduces the need for global state (in the MigrationItem class as class
fields) and with another step we can remove the global state entirely
and enable unit tests to create migration items without having to
worry about other unit tests.
Signed-off-by: Niels Thykier <niels@thykier.net>
The parsing of migration items should also look for the suite name in the
architecture part. This fixes the parsing for migration items like
some-src/amd64_tpu and some-src/amd64_tpu/1.0-1
Signed-off-by: Ivo De Decker <ivodd@debian.org>