fix: reduce cyclomatic complexity 33 in AWS provisioner

[dirien]

The AWS provisioner has a function with a very high cyclomatic

pkg/cloud/aws/aws.go:115:1: cyclomatic complexity 33 of func `(*Aws).CreateServer` is high (> 30) (gocyclo)
func (a *Aws) CreateServer(args automation.ServerArgs) (*automation.RessourceResults, error) {

We should split the fn to reduce the complexity