Remove submodule (version 2)

[erikbosch]

An alternative to #768

I did some more changes which I think would make sense to introduce for the upcoming 5.0, in short building on what Mr Schildt already have done.

In short - adding a release workflow that triggers build and uploads what we want to upload. Also removing the VERSION file as I do not really see that it is needed and using generic names for build artifacts making handling easier.

An example on how this could affect release handling.

• If we want to release a v1.6rc0 from master then we trigger the Draft release workflow stating 1.6.rc0 as version.
• That will build all artifacts and upload them to a draft release
• When publishing the release source code is added and tagging performed and we get something like https://github.com/erikbosch/vehicle_signal_specification/releases/tag/v1.6rc0
• (In a real release we should update release notes before publishing)

[erikbosch]

MoM:

• Presented
• Erik and Sebastian to agree on what to include for 5.0

[erikbosch]

I will include this one for 5.0 as it seems to work for the 5.0 needs. The other PR (#768) can then be seen as an add-on for 5.1 to introduce matrix builds.