scroll: more consistent scrolling behavior

Scrolling will always anchor the active note to the top of the screen

This is less confusing overall

Changelog-Changed: Clicking on a note will now always scroll it to the top
Signed-off-by: William Casarin <jb55@jb55.com>

damus/Models/ThreadModel.swift

@@ -189,7 +189,9 @@ class ThreadModel: ObservableObject {
         }
         
         if done {
-            loading = false
+            if (events.contains { ev in ev.id == initial_event.id }) {
+                loading = false
+            }
         }
     }