storcon: add https metrics for pageservers/safekeepers (#11460)

## Problem
Storcon will not start up if `use_https` is on and there are some
pageservers or safekeepers without https port in the database. Metrics
"how many nodes with https we have in DB" will help us to make sure that
`use_https` may be turned on safely.
- Part of https://github.com/neondatabase/cloud/issues/25526

## Summary of changes
- Add `storage_controller_https_pageserver_nodes`,
`storage_controller_safekeeper_nodes` and
`storage_controller_https_safekeeper_nodes` Prometheus metrics.

storage_controller/src/node.rs

@@ -89,6 +89,10 @@ impl Node {
         self.scheduling = scheduling
     }
 
+    pub(crate) fn has_https_port(&self) -> bool {
+        self.listen_https_port.is_some()
+    }
+
     /// Does this registration request match `self`?  This is used when deciding whether a registration
     /// request should be allowed to update an existing record with the same node ID.
     pub(crate) fn registration_match(&self, register_req: &NodeRegisterRequest) -> bool {