Use common action for dash

[erikbosch]

This PR does two things:

• It starts using a common action for dash in kuksa-actions. For now not using the "official" eclipse-kuksa repo as the action have not been merged there yet
• It puts the BOM generation and dash check in a separate job. Disadvantage is that that possibly causes the job to take somewhat longer as we may need to "redo" som setup steps like checkout. I put the job as follow up to build-container. It could run in parallel, but maybe we save some resource only running this job if build-container succeeds

Fixes #677

[erikbosch]

Replaced by #680