relay: split descriptors to {our,all}_descriptors

Now that we have ephemeral relays, we don't want them used everywhere

damus/Util/PostBox.swift

@@ -105,7 +105,7 @@ class PostBox {
             return
         }
         
-        let remaining = to ?? pool.descriptors.map { $0.url.id }
+        let remaining = to ?? pool.our_descriptors.map { $0.url.id }
         let posted_ev = PostedEvent(event: event, remaining: remaining, skip_ephemeral: skip_ephemeral)
         events[event.id] = posted_ev
         

damus/Util/Relays/RelayFilters.swift

@@ -83,7 +83,7 @@ func load_relay_filters(_ pubkey: String) -> Set<RelayFilter>? {
 }
 
 func determine_to_relays(pool: RelayPool, filters: RelayFilters) -> [String] {
-    return pool.descriptors
+    return pool.our_descriptors
         .map { $0.url.url.absoluteString }
         .filter { !filters.is_filtered(timeline: .search, relay_id: $0) }
 }