Proposal: SSLConnectionSocketFactory refactor to allow custom timer metrics on socket.connect

I'd like to add a timer metric around socket.connect in one of my classic blocking clients.

Usually, I can implement such a thing by subclassing or introducing a delagating implementation, adding a small piece of code to record metrics before delegating to the original implementation – this works incredibly well for PoolingHttpClientConnectionManager here, for example, which covers the full connect + handshake process across all ipaddrs resolved for the provided hostname.

Unfortunately, it's quite a bit more challenging to implement similar metrics over individual `Socket.connect` calls because they occur within a single large and complex method in SSLConnectionSocketFactory, which must delegate to other private methods: https://github.com/apache/httpcomponents-client/blob/19f3922b37369431d379ce57fa187740b22436cf/httpclient5/src/main/java/org/apache/hc/client5/http/ssl/SSLConnectionSocketFactory.java#L223-L266

Proposal:

I would like to introduce a new method along these lines:

void connectSocket(
    Socket sock,
    Timeout connectTimeout,
    HttpContext context)
    throws IOException

This way I can override the method and delegate to the builtin implementation, while timing only the socket.connect component of connection establishment.

Open questions:
1. Would you accept such a change?
2. The proposed example above uses the 'connectSocket' method name which would be overloaded with existing methods on ConnectionSocketFactory. Perhaps a more specific name like 'connectSocketTo' would be helpful here? Either way, I would need to provide javadoc describing the guarantee that only 'socket.connect' is handled.
3. Should such a new method be added as a default interface method on ConnectionSocketFactory, or a new protected method on the SSLConnectionSocketFactory implementation? Updating the implementation is the simpler change, but providing the method on the interface may be more extensible.

Feedback is always appreciated, thanks!