Fix k3s_server_location only working on default

- K3s has some absolute paths set in various places which cannot be
  changed. Using a symbolic link was the easiest fix. This is nice for
  running K3S on SBC that must boot to SD but K3S data should be stored
  on a faster drive.
- Other changes are for making the site playbook replayable without
  resetting the cluster. Ideally you can rerun it to check existing
  nodes or to add new ones.

Signed-off-by: Derek Nola <derek.nola@suse.com>