Change node autoscaler setup logic

[csengerszabo]

In step 4 of cluster creation at the Node Autoscaling part, there is a helper text saying: Enable "cluster-austoscaler" addon to apply these changes

If the addon is needed, and since this step is before we can add any addons to the cluster, it’s not logical to set this here.

Instead:

1. we can either set Node Autoscaler in the addon later
2. or enable the add-on previously in Step 2 under the Specifications section, then display this setting depending on the autoscaler was enabled previously

Option 2 is preferred.

[csengerszabo]

Evaluate if it’s possible to convert node autoscaler addon into an application, which will solve the UI logic since an application can be managed during cluster creation time

[ahmedwaleedmalik]

This parts need to be automated in a way that it's injected by KKP.

[csengerszabo]

• Setting up the autoscaler on the machine-deployments page on the UI
• If the check-box is selected, the application will automatically be added
• Implement simple templating for applicationDefinitions / installations considering the K8s version of the cluster
• Building the autoscaler Helm chart

[csengerszabo]

/milestone clear