* feat: builds with gox and buildx
This change builds all of Authelia respective binaries in parallel within a single step and distributes as necessary to subsequent steps, we now also build and distribute for the following OS/Architecture: freebsd/amd64.
Our CI/CD pipeline now also utilises docker buildx as a default for builds and pushes.
* refactor: clean up docker helper
* Remove `authelia-scripts docker push-image` command as all pushes will be performed with buildx and manifests
* Rename the --arch flag to --container
* Add Dockerfile.dev for users that want to build an Authelia container from source without utilising suites
* Set Dockerfile.dev as default for `authelia-scripts docker build` command
* refactor: variant -> container
