Implement Lokomotive updates using Nebraska library

[iaguis]

In flatcar/nebraska#419 a client library is proposed to handle updates workflow with Nebraska.

This is an umbrella issue to create a PoC of using the above mentioned library to trigger Lokomotive updates.

• Allow Lokomotive to be updated from a manifest and/or an artifact (#1528)
• Implement Lokomotive Update logic (#1529)
• Do updates
  • Add operator in Lokomotive to install components (#1366)
  • Investigate Helm Operator (#1530)

[iaguis]

A diagram of how this could work:

[iaguis]

I've updated the diagram with more details after #1530