This is a combination of experiments around docker CI on Gitlab performed in https://gitlab.wikimedia.org/addshore/test and Github actions CI that was added to https://github.com/addshore/mwcli
There is still room for improvement here, but lets get this merged (probably squash merged, because its 80 commits long) And move on from here.
Then we can stop split development between Gerrit Github etc.
There are some other changes made to code in this PR that I could try to split out too...
Change-Id: Ia91e5ab24ac1aeba3a7a255425430b0cead102cf