kubeadm: allow to provide patch inline in inventories

Specifying one directory for kubeadm patches is not ideal:
1. It does not allow working with multiples inventories easily
2. No ansible templating of the patch
3. Ansible path searching can sometimes be confusing

Instead, provide the patch directly in a variable, and add some quality
of life to handle components targeting and patch ordering more
explicitly (`target` and `type` which are translated to the kubeadm
scheme which is based on the file name)