[Flow][lib/node] Add closeAllConnections, closeIdleConnections to htt…

…ps$Server

Summary:
Add library defintions for:
 - [`https$Server.closeAllConnections()`](https://nodejs.org/api/http.html#servercloseallconnections) (Added v18.2.0)
 - [`https$Server.closeIdleConnections()`](https://nodejs.org/api/http.html#servercloseallconnections) (Added v18.2.0)

I originally added these to `http$Server` in D51232080 but missed `https$Server` - they should be on both.

Reviewed By: SamChou19815

Differential Revision: D58788947

fbshipit-source-id: a1d390b3f268365aa66fd6af0325d433e0467dd4

lib/node.js

@@ -1609,6 +1609,8 @@ declare class https$Server extends tls$Server {
     ...
   }, callback?: Function): this;
   close(callback?: (error: ?Error) => mixed): this;
+  closeAllConnections(): void;
+  closeIdleConnections(): void;
   keepAliveTimeout: number;
   headersTimeout: number;
   setTimeout(msecs: number, callback: Function): this;