Separate out "badges" for different stages

ATM, for each OS we have a single badge which summarizes
- git-annex built ok
- git-annex tested ok in multiple filesystem test scenarios
- datalad of 3 "versions" (`master, maint, release`) tested ok using this git-annex

It would have been nice to have at least 3 separate badges for each. That would be also of help for @joeyh since he would likely care mostly about only first 2.

But I am not sure how/if this could be accomplished.
Could we e.g. split into multiple workflows and somehow trigger one from another?
Or may be github is working on providing per step badges? (have not researched yet)

Any ideas @datalad/developers?