murano-mange import-package fails to parse tags

[ruhe]

Steps to reproduce:
1. Checkout murano-api
2. Generate DB:
    tox -e venv -- murano-manage --config-file $PATH_TO_MURANO_CONFIG db-sync
3. Uncomment #'tags': pkg.tags in murano-api/muranoapi/cmd/manage.py
3. Try to import AD service:
    tox -e venv -- murano-manage --config-file $PATH_TO_MURANO_CONFIG import-package $MURANO_API_SRC/meta/io.murano.windows.ActiveDirectory

Operation will fail because ApplicationPackage.tags is None. We need to find out why tags wasn't initialized during package import and fix that.

Note:
Patch with this issue is not merged yet https://review.openstack.org/#/c/86039