ci: Generate and build codegen test samples

[calvincestari]

Task here is to have CI re-generate the targets we use for codegen testing (AnimalKingdomAPI, UploadAPI, StarwarsAPI, SubscriptionAPI) code and use swift build to validate it compiles - will need to be a Swift package.

[calvincestari]

These test samples exist already at https://github.com/apollographql/apollo-ios/tree/release/1.0/Tests/TestCodeGenConfigurations but we still need to implement the CI checks on them.