github actions: Download deps before unit tests

Add lz4 and tar to iso

Unify downloaders, add GitHub and Alibaba ISO fallbacks

We can use preloaded tarballs for VMs as well, but this requires both
lz4 and tar to be installed to that the tarball can be extracted
correctly within the VM.

Since preloaded tarballs are container runtime specific, I added a Preload() func
to the cruntime interface. To use  it with VMs, the tarball is first
copied into the VM and then extracted. The leftover tarball is deleted,
and the container runtime (currently only docker is supported) is
restarted.

Fallback to vm-driver parameter

fix wording for docker/podman drivers to "container"

Upgrade cni and cni-plugins to spec 0.4.0

Relates to https://github.com/kubernetes/minikube/issues/6859

Decouple machine name from profile/cluster name

Only cache k8s images if necessary

Switch --vm-driver paramter to --driver

Fix inverted certificate symlink creation logic

Add k8s binaries to preloaded tarball

give hint if 'minikube delete' cannot delete the machine directory