Add test to cover mutation conventions using naming conventions (#4803)

[PHILLIPS71]

As discussed in Slack it adds a failing test to display the issues using mutation conventions with naming conventions as outlined in #4803.

I'm unsure if the naming conventions should be applied before or after the mutation convention interceptor is applied which would result in differing type names (eg; DoSomething_TypeNamedPayload vs DoSomethingPayload_TypeNamed), if it's the latter let me know and I can update the snapshot.

[CLAassistant]

All committers have signed the CLA.