[Feat]: Change from nexus API to GraphQL

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https://github.com/Nexus-Mods/sso-integration-demo

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Asked Nexus Staff for app approval. Waiting for answer

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New Information from nexus staff: Apparently there is a new GraphQL API that doesn't need authorization for our needs anyway, so switching to that will solve the API problem.
https://graphql.nexusmods.com/