Don't offer Mark As Unread for chats with topics (#190)

For groups with topics, channel direct messages and bots with topics,
TelegramCore's unread toggle only marks topics as read, so Mark As Unread
in the chat list did nothing. As on iOS, the context menu and VoiceOver
actions no longer offer it, the swipe button is left out when nothing is
unread, and a row with nothing to show on the left doesn't slide.

Author: null00x

packages/ChatListUI/Sources/ChatListUI/ChatListRowItem.swift

@@ -1522,7 +1522,11 @@ public class ChatListRowItem: TableRowItem {
     }
 
     public var markAsUnread: Bool {
-        return !isSecret && !isUnreadMarked && badgeNode == nil && !showsMentionSlot && !self.mode.savedMessages
+        return !isSecret && !isUnreadMarked && badgeNode == nil && !showsMentionSlot && !self.mode.savedMessages && peer?.isForumOrMonoForum != true
+    }
+
+    public var canToggleUnread: Bool {
+        return peer?.isForumOrMonoForum != true || badgeNode != nil || showsMentionSlot || isUnreadMarked
     }
 
     public func collapseOrExpandArchive() {

packages/ChatListUI/Sources/ChatListUI/ChatListRowView.swift

@@ -2734,7 +2734,7 @@ public class ChatListRowView: TableRowView, RevealTableView {
             }
 
 
-            if !item.isTopic {
+            if !item.isTopic, item.canToggleUnread {
                 revealLeftView.addSubview(unread)
                 revealLeftView.backgroundColor = .clear
             }
@@ -2872,6 +2872,7 @@ public class ChatListRowView: TableRowView, RevealTableView {
     private var animateOnceAfterDelta: Bool = true
     private var revealHighlighted: Bool = false
     public func moveReveal(delta: CGFloat) {
+        let delta = revealLeftView.subviews.isEmpty ? min(delta, 0) : delta
 
         if !revealHighlighted, delta != 0, let item = item as? ChatListRowItem, !item.isSelected, let table = item.table {
             _ = table.highlight(item: item)