Look into GraphQL Codegen config improvements

[bchu1]

https://the-guild.dev/graphql/codegen/plugins/typescript/typescript-operations

Worth looking into:

• avoidOptionals - remove unnecessary ?:s on fields. It's also possible to not apply this to inputs if we don't want to also change maybeValue to T | undefined (otherwise it'll require input objects to specify all unused fields as null).
• immutableTypes
• maybeValue - changing to T | undefined in conjunction with avoidOptionals can allow us to remove nulls from the codebase.