Fix function refs in variable validation

[cam72cam]

The nodeModuleVariable.References() function is not called within the function transformer as it is on an expanded object. Instead these references are determined pre-expansion and provided to the provider function transformer

I still need to try to find a test case that explicitly triggers this, instead of the race condition in the issue.

Resolves #2051

Target Release

1.9.0,1.8.4,1.7.4

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[github-actions]

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