Support ClientProperties.PROXY_URI & al in HttpUrlConnector

[jbescos]

Relates to #5089

I don't know what is jnh-connector, Jetty?. That connector is probably not implemented in this PR.

[senivam]

jnh-connector (JavaNetHttp connector) relates to Jersey 3.1.+

[jbescos]

jnh-connector (JavaNetHttp connector) relates to Jersey 3.1.+

I am going to postpone that connector because I am working in master. After this is merged I will cherry-pick it and add JavaNetHttp for the branch 3.1.

[jbescos]

There is one issue with the system property 'http.nonProxyHosts' in some connectors.

Internally every connector has its own client (Apache, Jetty, etc), and it is configured in the constructor of the connector. The proxy is part of this configuration. Then the client is re-used in different requests.

'http.nonProxyHosts' depends on runtime data, because we need to check the current URI of the request in order to enable or disable the proxy, but note that the proxy was already configured before in the constructor.

I don't see a good option to address this. In my opinion there are 3:
1 - Do not support any proxy system properties and delegate that on the implementation (Apache, Jetty, etc). In case they don't support it, we don't support it.
2 - In case we really must support this, we could create 2 clients in every connector, one with the proxy and other without proxy. In runtime we select the proper one comparing the host in http.nonProxyHosts with the current request URI.
3 - We can ignore the http.nonProxyHosts in the connectors where there is this issue.

In my opinion we should go for option 1, because option 2 is memory and performance inefficient, and the different implementations can deal with this with no problem because they have access to system properties.