Use matrix and Makefile to build both images in the same workflow.
Kanidmd image remove muslc version and come back to SUSE version because
performance problems.
Also fix a typo bug with kanidmd image build on CI.
- Change base builder image to `ekidd/rust-musl-builder` for create static
binaries.
- Add two flavours: alpine and stand alone binary.
- Add makefile commands for build, test and push kanidmd images and
refactor previous code.
- Add missing things to `.dockerignore`.
- Refactor CI to use Makefile.