feat: support docker volume type and size

[okozachenko1203]

fix #4

[okozachenko1203]

@mnaser i think we need to solve the followings still;

• detect the correct disk name for etcd and docker volume respectively among multiple data volumes, and use preKubeadmCommands https://github.com/kubernetes-sigs/cluster-api/blob/main/docs/proposals/20200423-etcd-data-disk.md#use-script-to-do-the-etcd-mount-and-append-that-script-to-prekubeadmcommands
• json patches tricks for cases; etcd volume used, docker volume used, both used

[okozachenko1203]

recheck

[mnaser]

I'm not sure why we have multiple cases here instead of simply using json patches that layer up onto each other.