Move Nomad job creation to Nomad package

Previously, low level Nomad job creation was done in the environment manager.
It used many functions of the nomad package so we felt like this logic
better belongs to the nomad package.

nomad/nomad.go

@@ -32,6 +32,12 @@ type ExecutorAPI interface {
 	// LoadRunners loads all runners of the specified environment which are running and not about to get stopped.
 	LoadRunners(environmentID string) (runnerIds []string, err error)
 
+	// RegisterTemplateJob creates a template job based on the default job configuration and the given parameters.
+	// It registers the job and waits until the registration completes.
+	RegisterTemplateJob(defaultJob *nomadApi.Job, environmentID int,
+		prewarmingPoolSize, cpuLimit, memoryLimit uint,
+		image string, networkAccess bool, exposedPorts []uint16) (*nomadApi.Job, error)
+
 	// LoadEnvironmentTemplate loads the template job of the specified environment.
 	// Based on the template job new runners can be created.
 	LoadEnvironmentTemplate(environmentID string) (*nomadApi.Job, error)
@@ -98,7 +104,7 @@ func (a *APIClient) LoadEnvironmentTemplate(environmentID string) (*nomadApi.Job
 }
 
 func (a *APIClient) MonitorEvaluation(evaluationID string, ctx context.Context) error {
-	stream, err := a.EvaluationStream(evaluationID, ctx)
+	stream, err := a.apiQuerier.EvaluationStream(evaluationID, ctx)
 	if err != nil {
 		return fmt.Errorf("failed retrieving evaluation stream: %w", err)
 	}