[Windows] Make k3s compatible to be run as a service on Windows OS

[caroline-suse-rancher]

Generally, k3s should be able to be run as a service. In the current implementation of k3s for Windows in this issue, this isn't a capability. Ideally, it should be and the service should be available for installation via a script, similar to what we offer on linux.

[brandond]

Rather than having K3s manage installing itself as a Windows service (as RKE2 does) we should document or automate use of NSSM as a service wrapper: https://community.chocolatey.org/packages/nssm

Despite the somewhat silly name this is a GREAT project, I wish we'd used it for RKE2 instead of rolling our own Windows service management code.

Edit: Apparently NSSM is no longer maintained. I guess we should use something else. Regardless we should not roll our own service management and repeat the issues we have run into with logging and service management for RKE2 on windows.