ci: enable github actions via docker

[fnrizzi]

CI runs, but needs to be improved via docker or something similar.
Right now, the CI builds EVERY time Kokkos{core, kernels}, so we need to make images for these and use those.

[fnrizzi]

• we need to make docker images for core and kernels.
• we only need Serial and OpenMP backends for now: please propose a naming convention
• you can upload all these to our pressio docker hub page
• one thing to keep in mind is that we need also this yamlcpp tpl to be part of the images