Allow @GRpcService on @Bean factory methods

I wonder if it’s high effort to implement such feature

For example we use a mix of dependency-injection approaches/recommendations, as the result, we already have a factory that produces GrpcServices. Would be nice if we could reuse everywhere and make sure that our tests use the same code/config as prod code

@GRpcService
@Bean 
public MyGrpcService myGrpcService(ApplicationFactory factory) {
    factory.getMyGrpcService()
}

[bitbrain]

@jvmlet within this code https://github.com/LogNet/grpc-spring-boot-starter/blob/19fc75177a40d5b7b64cf6dcde81dfd4bb9a5eb9/grpc-spring-boot-starter/src/main/java/org/lognet/springboot/grpc/autoconfigure/OnMissingErrorHandlerCondition.java#L29 we are using getBeanClassName which does not work on @Bean factory methods. I will raise a pull request to fix this now.

[jvmlet]

With SB 2.5.x this should work OOTB. Will try to confirm tomorrow