refactor and cleanup [skip ci]

submodules/Postbox/Sources/ChatListHolesView.swift

@@ -0,0 +1,27 @@
+import Foundation
+
+public struct ChatListHolesEntry: Hashable {
+    public let groupId: PeerGroupId
+    public let hole: ChatListHole
+}
+
+final class MutableChatListHolesView {
+    fileprivate var entries = Set<ChatListHolesEntry>()
+    
+    func update(holes: Set<ChatListHolesEntry>) -> Bool {
+        if self.entries != holes {
+            self.entries = holes
+            return true
+        } else {
+            return false
+        }
+    }
+}
+
+public final class ChatListHolesView {
+    public let entries: Set<ChatListHolesEntry>
+    
+    init(_ mutableView: MutableChatListHolesView) {
+        self.entries = mutableView.entries
+    }
+}