crossrepomove: fix moving debug packages to the target repo
We did not copy over the optional debug packages to the staging environment before db-updating the moved state. Afterwards the db-remove call removed the debug packages from the source repo. This lead to dropping debug packages when using crossrepomove.
This approach ensures we have a uniform shell to avoid shell glob behavior inconsistencies. The copy of the package path is mandatory and will error out if missing while the debug package path is optional as reflected by a subshell that succeeds either way.
Fixes #92 (closed)