move some stuff around, reply desc

Signed-off-by: William Casarin <jb55@jb55.com>

damus/Models/Reply.swift

@@ -0,0 +1,32 @@
+//
+//  Reply.swift
+//  damus
+//
+//  Created by William Casarin on 2022-05-08.
+//
+
+import Foundation
+
+struct ReplyDesc {
+    let pubkeys: [String]
+    let others: Int
+}
+
+func make_reply_description(_ tags: [[String]]) -> ReplyDesc {
+    var c = 0
+    var ns: [String] = []
+    var i = tags.count - 1
+        
+    while i >= 0 {
+        let tag = tags[i]
+        if tag.count >= 2 && tag[0] == "p" {
+            c += 1
+            if ns.count < 2 {
+                ns.append(tag[1])
+            }
+        }
+        i -= 1
+    }
+        
+    return ReplyDesc(pubkeys: ns, others: c)
+}