Add vJunos-Evolved node definition

[kelvintechie1]

Add in a custom node definition for the Juniper vJunos-Evolved (aka vPTX/vEVO) virtual router device type. Also, add in the associated instructions to import the node definition and configure CML to boot the node in UEFI mode

[conceptual-perception]

Reviewed with Kelvin over Discord Chat.

My requested changes:

1. Specify which file to download, in this case, the qcow2.
2. CML node definitions end in .yaml
3. Please call the service the rescue shell (port 1122), and include a link to how to enable it as a kindness.
4. the folders for the EFI stuff go on all the nodes, if it's a cluster.
5. Add "login is root no password"

[kelvintechie1]

All requested changes made!