refactor(vars): add system/hypervisor dict inputs

templates/xen.cfg.j2

@@ -0,0 +1,17 @@
+builder = "hvm"
+name = "{{ hostname }}"
+memory = "{{ system_cfg.memory_mb }}"
+vcpus = "{{ system_cfg.cpus }}"
+disk = [
+{%- for disk in virtualization_xen_disks | default([]) -%}
+  'file:{{ disk.path }},{{ disk.target }},w'{% if not loop.last or xen_installer_media_enabled | bool %}, {% endif %}
+{%- endfor -%}
+{%- if xen_installer_media_enabled | bool -%}
+  '{{ boot_iso }},,hdc,cdrom'{% if rhel_iso is defined and rhel_iso | length > 0 %}, '{{ rhel_iso }},,hdd,cdrom'{% endif %}
+{%- endif -%}
+]
+vif = [ 'bridge={{ system_cfg.network }},model=e1000' ]
+boot = "{{ 'dc' if xen_installer_media_enabled | bool else 'c' }}"
+on_crash = "preserve"
+on_poweroff = "destroy"
+serial = "pty"