Ensure Azure-related gems are loaded

What does this MR do and why?

We attempted to load the gitlab-fog-azure-rm only if it was really needed for object storage, but there are a number of cases where we don't dynamically load these gems when we need them. To avoid the complexity of this dynamic allocation, we now require the gem, just as we do with other object storage providers. Unfortunately this adds 5 MB to the RAM usage of the process according to derailed_benchmarks, but this is fairly typical for a gem for object storage.

Relates to #334853 (closed)

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