Add HA option, change to yaml inventory, cleanup

- HA option for multiple server nodes using embedded etcd
- Switch to yaml inventory file for easier editing and combining vars
- Update to full ansible module names
- Change master/node names to server/agent
- Cleanup small linting errors
- Add reboot playbook which staggers reboot to keep HA cluster up
- Move playbooks to playbook directory

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

roles/k3s/agent/tasks/main.yml

@@ -0,0 +1,15 @@
+---
+- name: Copy K3s service file
+  ansible.builtin.template:
+    src: "k3s.service.j2"
+    dest: "{{ systemd_dir }}/k3s-agent.service"
+    owner: root
+    group: root
+    mode: 0755
+
+- name: Enable and check K3s service
+  ansible.builtin.systemd:
+    name: k3s-agent
+    daemon_reload: yes
+    state: restarted
+    enabled: yes