Make seatservice-example container testable

[vasilvas99]

• Update seatservice container to version v0.3.0 and clean-up manifest
• Update databroker to v0.3.0
• Add sdv-ctr-exec utility script to easily execute stripts inside containers
• Update recipes for container manifest deployment

[vasilvas99]

Closed since the default behavior of seatservice-example should be virtual can and bridge networking.