Support Forwarded header "by" parameter in ForwardedHeaderFilter

[expuss2000]

Spring doesn't parse the "by" parameter of the Forwarded header in ForwardedHeaderFilter.

According to RFC 7239:

The "by" parameter is used to disclose the interface where the request came in to the proxy server.

I think it should override getLocalAddr/getLocalPort of the HttpServletRequest: https://jakarta.ee/specifications/servlet/6.0/apidocs/jakarta.servlet/jakarta/servlet/servletrequest#getLocalAddr()

The syntax of a "by" value is the same of the "for" parameter.

Support for the "for" parameter has been added as requested in #23260

[bclozel]

Superseded by #34683