Artifacts should be sent as artifact created and published instead

[t-persson]

Description

Instead of attaching artifacts as logs to the TestSuiteFinished when they are in fact test artifacts we should send ArtifactCreated and Published instead.

Motivation

It's more in-line with Eiffel and would be easier for ETOS Client to deal with the storage of reports and artifacts.

Exemplification

ETOS Client stores reports and artifacts into separate folders. This change would help with that.

Benefits

Better traceability and we're using the Eiffel specification better.

Possible Drawbacks

A lot more events to send.

[t-persson]

Discussions in regards to which https://github.com/package-url/purl-spec type we shall use have started.
If these discussions do not end within the deadline of this milestone, then we shall remove this issue from the milestone.

[t-persson]

Due to the requirement to do a change in etos client as well as the testing required, we will move this issue from Version 1.3.0 to 1.4.0 instead.