Implement rate-limiting to securize our app, handling DDoS attacks and more

[TheRustifyer]

Although applying security checks on api-gateway is a necessity, it is not enough to prevent attacks such as DDoS (just ask T1). So, considering our resources, we need a mechanism to monitor, control, and limit the number of requests we recieve/process. This is what the Spring Cloud Gateway does for us. In this issue, I am going to implement rate limiting tasks thanks to the powerful integration of Spring with Redis, so to summarize, I'll be adding a redis via docker to the api-gateway that provides our ag a mechanism to handle backpressure and other rate and consumption tasks, making our gateway much more resilient and reliable.