This commit auto-configures HTTP resource factories on both Reactor
Netty and Jetty server instances. This creates `ReactorResourceFactory`
and `JettyResourceFactory` beans when necessary - those beans can be
reused and applied by the client auto-configuration in order to share
resources between client and server for optimal performance.
The server auto-configuration has the highest precedence, so from now
on, the auto-configured ResourceFactory bean on the client side will be
skipped if a reactive server is configured.
Closes gh-14495
2588a71ac4