Pending Zaps

A fairly large change that replaces Zaps in the codebase with "Zapping"
which is a tagged union consisting of a resolved Zap and a Pending Zap.
These are both counted as Zaps everywhere in Damus, except pending zaps
can be cancelled (most of the time).

damus/Views/Events/TextEvent.swift

@@ -181,7 +181,9 @@ struct TextEvent: View {
             VStack(alignment: .leading) {
                 TopPart(is_anon: is_anon)
                 
-                ReplyPart
+                if !options.contains(.no_replying_to) {
+                    ReplyPart
+                }
                 
                 EvBody(options: self.options)