copy dmd's azure pipelines

[thewilsonator]

so that breakages like #2689 won't happen again.

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[thewilsonator]

This is currently just a direct copy of DMD's it will likely need be adapted. (e.g. It doesn't appear to be triggering on this PR).

cc @Geod24

[Geod24]

Yeah you probably need to configure something on Azure's side, for which you'll need @wilzbach .
And we should be dropping AppVeyor I suppose.

[wilzbach]

Instead of duplicating all these tedious files, it might be better to reuse at least the lib files to avoid more out of sync files.