Add muting and mutelists

- Filter muted posts from feed on mute
- List muted users in sidebar

Changelog-Added: Added ability to block users

damus/Views/Muting/MutelistView.swift

@@ -0,0 +1,67 @@
+//
+//  MutelistView.swift
+//  damus
+//
+//  Created by William Casarin on 2023-01-25.
+//
+
+import SwiftUI
+
+struct MutelistView: View {
+    let damus_state: DamusState
+    @State var users: [String]
+    
+    func RemoveAction(pubkey: String) -> some View {
+        Button {
+            guard let mutelist = damus_state.contacts.mutelist else {
+                return
+            }
+            
+            guard let keypair = damus_state.keypair.to_full() else {
+                return
+            }
+            
+            guard let new_ev = remove_from_mutelist(keypair: keypair, prev: mutelist, to_remove: pubkey) else {
+                return
+            }
+            
+            damus_state.contacts.set_mutelist(new_ev)
+            damus_state.pool.send(.event(new_ev))
+            users = get_mutelist_users(new_ev)
+        } label: {
+            Label(NSLocalizedString("Delete", comment: "Button to remove a user from their blocklist."), systemImage: "trash")
+        }
+        .tint(.red)
+    }
+
+    
+    var body: some View {
+        List(users, id: \.self) { pubkey in
+            UserView(damus_state: damus_state, pubkey: pubkey)
+                .id(pubkey)
+                .swipeActions {
+                    RemoveAction(pubkey: pubkey)
+                }
+        }
+        .navigationTitle("Blocked Users")
+    }
+}
+
+
+func get_mutelist_users(_ mlist: NostrEvent?) -> [String] {
+    guard let mutelist = mlist else {
+        return []
+    }
+    
+    return mutelist.tags.reduce(into: Array<String>()) { pks, tag in
+        if tag.count >= 2 && tag[0] == "p" {
+            pks.append(tag[1])
+        }
+    }
+}
+
+struct MutelistView_Previews: PreviewProvider {
+    static var previews: some View {
+        MutelistView(damus_state: test_damus_state(), users: [test_event.pubkey, test_event.pubkey+"hi"])
+    }
+}