Rename `pkg/api/flamenco-manager.yaml` to `flamenco-openapi.yaml`, to
distinguish the OpenAPI definition file from the Flamenco Manager
configuration file of the same name (but in a different directory).
No functional changes.
- Addon switches between filesystem-packing and Shaman-packing
automatically, depending on whether the Manager has Shaman enabled.
- Actually using BAT for Shaman packing.
It doesn't work though, some error occurs when receiving Shaman response
from the Manager in the Addon.