Spot Instances for user pools

[Gordonby]

PR Summary

Adds support for VM Spot Instances for the user pool.

If using just the system pool then Spot Instances are not allowed, disabled in the UI and excluded from the deployment script generation.

Closes #610

PR Checklist

• PR has a meaningful title
• Summarized changes
• This PR is ready to merge and is not Work in Progress
• Link to a filed issue
• Screenshot of UI changes (if PR includes UI changes)

[Gordonby]

I have had trouble testing this in my subscription because of Spot Instance availability... That's another problem that i'll try and get fixed 🚀

Test with;
az deployment group create -g innerloop --template-file ./bicep/main.bicep --parameters resourceName=az-k8s-ka nodePoolSpot=true aksOutboundTrafficType=natGateway agentVMSize=Standard_DS2_v2 osDiskSizeGB=32 location=eastus

[github-actions]

PR smells stale, no activity for 30 days. Stale Label will be removed if the PR is updated, otherwise closed in a month.

[github-actions]

PR smells stale, no activity for 30 days. Stale Label will be removed if the PR is updated, otherwise closed in a month.

[Gordonby]

Tested with;

git clone -b gb-spotvm https://github.com/Gordonby/AKS-Construction
cd AKS-Construction/
cd bicep/
bicep build main.bicep
az deployment group create -g innerloop  --template-file main.bicep --parameters resourceName=az-k8s-ka nodePoolSpot=true aksOutboundTrafficType=natGateway agentVMSize=Standard_DS2_v2 osDiskSizeGB=32 location=eastus agentCount=1

Outputs

[pjlewisuk]

LGTM, happy to merge