Migrate audit.net internals to share code with DevAudit

[OSSIndex-Admin]

There is some duplicate functionality between audit.net and DevAudit. We should use code from DevAudit to provide this common functionality.

In so doing the main artifacts generated by the audit.net build should not change, in particular the *.visx file should have the same name and properties so that the next release has the same appearance at the previous. New dependencies are fine (for example, a dependency with DevAudit is likely required).

[OSSIndex-Admin]

When we take this on, we need to be certain not to break result filtering.