Lift pinned timelines modifiers up to CustomizeTimelinesList

.sheet on a Section with a header does not work, and produces warnings
about trying to present on a VC that already has a presentation. It
seems like the .sheet modifier is being applied to both the Section
content and header?

Fixes #514

Tusker/Screens/Customize Timelines/CustomizeTimelinesView.swift

@@ -13,7 +13,7 @@ struct CustomizeTimelinesView: View {
     let mastodonController: MastodonController
     
     var body: some View {
-        CustomizeTimelinesList()
+        CustomizeTimelinesList(pinnedTimelines: mastodonController.accountPreferences.pinnedTimelines)
             .environmentObject(mastodonController)
             .environment(\.managedObjectContext, mastodonController.persistentContainer.viewContext)
     }
@@ -26,6 +26,14 @@ struct CustomizeTimelinesList: View {
     @FetchRequest(sortDescriptors: []) private var filters: FetchedResults<FilterMO>
     @Environment(\.dismiss) private var dismiss
     @State private var deletionError: (any Error)?
+    // store this separately from AccountPreferences in the view, b/c the @LazilyDecoding wrapper breaks animations
+    @State private var pinnedTimelines: [PinnedTimeline]
+    @State private var isShowingAddHashtagSheet = false
+    @State private var isShowingAddInstanceSheet = false
+    
+    init(pinnedTimelines: [PinnedTimeline]) {
+        self.pinnedTimelines = pinnedTimelines
+    }
 
     var body: some View {
         if #available(iOS 16.0, *) {
@@ -50,7 +58,11 @@ struct CustomizeTimelinesList: View {
     
     private var navigationBody: some View {
         List {
-            PinnedTimelinesView(accountPreferences: mastodonController.accountPreferences)
+            PinnedTimelinesView(
+                pinnedTimelines: $pinnedTimelines,
+                isShowingAddHashtagSheet: $isShowingAddHashtagSheet,
+                isShowingAddInstanceSheet: $isShowingAddInstanceSheet
+            )
             .appGroupedListRowBackground()
             
             Section {
@@ -99,6 +111,12 @@ struct CustomizeTimelinesList: View {
                 }
             }
         }
+        .modifier(PinnedTimelinesModifier(
+            accountPreferences: mastodonController.accountPreferences,
+            pinnedTimelines: $pinnedTimelines,
+            isShowingAddHashtagSheet: $isShowingAddHashtagSheet,
+            isShowingAddInstanceSheet: $isShowingAddInstanceSheet
+        ))
         .alertWithData("Error Deleting Filter", data: $deletionError, actions: { _ in
             Button("OK") {
                 self.deletionError = nil

Tusker/Screens/Customize Timelines/PinnedTimelinesView.swift

@@ -11,17 +11,10 @@ import Pachyderm
 
 struct PinnedTimelinesView: View {
     @EnvironmentObject private var mastodonController: MastodonController
-    @ObservedObject private var accountPreferences: AccountPreferences
     
-    @State private var isShowingAddHashtagSheet = false
+    @Binding var pinnedTimelines: [PinnedTimeline]
-    @State private var isShowingAddInstanceSheet = false
+    @Binding var isShowingAddHashtagSheet: Bool
-    // store this separately from AccountPreferences in the view, b/c the @LazilyDecoding wrapper breaks animations
+    @Binding var isShowingAddInstanceSheet: Bool
-    @State private var pinnedTimelines: [PinnedTimeline]
-    
-    init(accountPreferences: AccountPreferences) {
-        self.accountPreferences = accountPreferences
-        self.pinnedTimelines = accountPreferences.pinnedTimelines
-    }
     
     var body: some View {
         Section {
@@ -110,6 +103,17 @@ struct PinnedTimelinesView: View {
         } header: {
             Text("Pinned Timelines")
         }
+    }
+}
+
+struct PinnedTimelinesModifier: ViewModifier {
+    let accountPreferences: AccountPreferences
+    @Binding var pinnedTimelines: [PinnedTimeline]
+    @Binding var isShowingAddHashtagSheet: Bool
+    @Binding var isShowingAddInstanceSheet: Bool
+
+    func body(content: Content) -> some View {
+        content
             .sheet(isPresented: $isShowingAddHashtagSheet, content: {
                 #if os(visionOS)
                 AddHashtagPinnedTimelineView(pinnedTimelines: $pinnedTimelines)