Pulumi: Add smoke tests

[jemrobinson]

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⤴️ Summary

• Add some basic smoke tests (NB. these use the old version of bats available in the Ubuntu repos which has fewer features)
• Add a FileUpload provider to allow files to be uploaded to VMs that cannot access e.g. raw.githubusercontent.com
• Add an AzureApi call that runs a remote script, but catches failures caused by existing scripts and retries

🌂 Related issues

Closes #1603

🔬 Tests

Tested on a local deployment

[JimMadge]

Looks good.

The Azure API doesn't have a more direct way to write a file to a disk mounted to a VM?
I suppose we use the API here as the machines will not generally be accessible by SSH?

[jemrobinson]

The Azure API doesn't have a more direct way to write a file to a disk mounted to a VM?

No, weirdly not. Maybe they didn't want to write something that would work cross-OS?

I suppose we use the API here as the machines will not generally be accessible by SSH?

That's right - these VMs have a very limited allowed set of connections in and out which only cover internal DSH connections and platform level stuff (like this) which bypasses the NSG rules.