Nomad decoupling

[efbar]

Add possibility to not install Nomad in the provisioning process.

Assigned to @efbar

• AWS: https://github.com/bitrockteam/caravan-infra-aws/issues/34
  • [x] disable in bootstrap phase
  • [x] debugging and testing

Assigned to @ripa1993

• Azure: https://github.com/bitrockteam/caravan-infra-azure/issues/36
  • [ ] disable in bootstrap phase
  • [ ] debugging and testing