FGB: Do not share the test store with all test modules

[aaime]

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[aaime]

@jodygarnett @groldan here is the updated version using programmatic store registration.

Plus: the test datastore is not shared among all modules
Cons: we don't see anymore when the other modules have issues with data store lookup, like in the original patch.

Wondering if I should update all the tests for the areas that I've found and fixed, so that they also programmatically register the test store. Of course... this will protect only those code path. Any new code path doing a store lookup without considering the store type won't be caught.

[jodygarnett]

I think it is a solid improvement.

If those have been found and fixed, maybe do a couple as an example but it is not a worry. Instead it is good to have this on hand as an example for any new codepath that needs to check.