Remove HttpClient Interfaces and Classes

[ryanjbaxter]

The classes and interfaces in org.springframework.cloud.commons.httpclient are only used by Spring Cloud OpenFeign. Other projects no longer use them. We can remove these classes and interfaces and move the necessary code to Spring Cloud OpenFeign. In addition Spring Framework 6 has removed support for Apache HttpClient v4 so we should be using HttpClient v5, which OpenFeign already has support for.

[akhgeek30]

@ryanjbaxter Since the package is removed, and move to OpenFeign, where can I find the OkHttpClientConnectionPoolFactory, and OkHttpClientFactory classes?

[ryanjbaxter]

It is not used anymore since we no longer need those abstractions
spring-cloud/spring-cloud-openfeign#788

[sshefferly]

@ryanjbaxter Given this change, I assume the HTTP Client Factory documentation at
https://docs.spring.io/spring-cloud-commons/reference/4.2.1/spring-cloud-commons/common-abstractions.html#http-clients
is now irrelevant/incorrect?
What is now the best way to customize the Apache HttpClient 5 connection pool? (Stack Overflow: https://stackoverflow.com/questions/79597280/configure-max-http-connections-on-spring-cloud-gateway-mvc-route )

[ryanjbaxter]

Good find I removed that documentation 99e710d

Can you open an issue in Spring Cloud Gateway regarding your gateway configuration question