Rate limiting with service middleware

Now that we have built a complete service, we are going to see how easy it is to add middleware to our endpoints in order to extend the service without touching the actual implementations themselves.

In real-world services, it is sensible to limit the number of requests it will attempt to handle so that the service doesn't get overwhelmed. This can happen if the process needs more memory than is available, or we might notice performance degradation if it eats up too much of the CPU. In a micro-service architecture, the strategy to solving these problems is to add another node and spread the load, which means that we want each individual instance to be rate limited.

Since we are providing the client, we should add rate limiting there, which would prevent too many requests from getting on the network. But it is also sensible to add rate limiting to the server in case many clients are trying to access the same services at the same time. Luckily, endpoints...