pool: skip ephemeral relays by default

Also filter relays by read/write once we introduce that

damus/Nostr/RelayPool.swift

@@ -180,10 +180,22 @@ class RelayPool {
         request_queue.append(QueuedRequest(req: r, relay: relay))
     }
     
-    func send(_ req: NostrRequest, to: [String]? = nil) {
+    func send(_ req: NostrRequest, to: [String]? = nil, skip_ephemeral: Bool = true) {
         let relays = to.map{ get_relays($0) } ?? self.relays
 
         for relay in relays {
+            if req.is_read && !relay.descriptor.info.read {
+                continue
+            }
+            
+            if req.is_write && !relay.descriptor.info.write {
+                continue
+            }
+            
+            if relay.descriptor.info.ephemeral && skip_ephemeral {
+                continue
+            }
+            
             guard relay.connection.isConnected else {
                 queue_req(r: req, relay: relay.id)
                 continue
@@ -194,6 +206,7 @@ class RelayPool {
     }
     
     func get_relays(_ ids: [String]) -> [Relay] {
+        // don't include ephemeral relays in the default list to query
         relays.filter { ids.contains($0.id) }
     }