Upgrade tests to Nunit3

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upgrading to version includes some breaking changes.

Steps

• [x] Update to latest version 2 of Nunit
• [x] Add NUnit.Migrator to all test projects
• [x] Follow the auto fix instructions
• [x] Upgrade nuget package to Nunit3 and add Nunit3TestAdapter
• [x] remove NUnit.Migrator

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complete

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