[TUI] Add GoTo Sector dialog for improved sector navigation

Aaru.Tui/ViewModels/Dialogs/GoToSectorDialogViewModel.cs

@@ -0,0 +1,62 @@
+using System.Windows.Input;
+using Avalonia.Controls;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+
+namespace Aaru.Tui.ViewModels.Dialogs;
+
+public sealed partial class GoToSectorDialogViewModel : ViewModelBase
+{
+    readonly ulong  _maxSector;
+    internal Window _dialog = null!;
+
+    [ObservableProperty]
+    string _errorMessage = string.Empty;
+
+    [ObservableProperty]
+    bool _hasError;
+
+    [ObservableProperty]
+    string _sectorNumber = string.Empty;
+
+    public GoToSectorDialogViewModel(Window dialog, ulong maxSector)
+    {
+        _dialog       = dialog;
+        _maxSector    = maxSector;
+        OkCommand     = new RelayCommand(Ok);
+        CancelCommand = new RelayCommand(Cancel);
+    }
+
+    public ulong? Result { get; private set; }
+
+    public ICommand OkCommand     { get; }
+    public ICommand CancelCommand { get; }
+
+    void Ok()
+    {
+        if(!ulong.TryParse((string?)SectorNumber, out ulong sector))
+        {
+            ErrorMessage = "Please enter a valid number.";
+            HasError     = true;
+
+            return;
+        }
+
+        if(sector > _maxSector)
+        {
+            ErrorMessage = $"Sector number must be less than or equal to {_maxSector}.";
+            HasError     = true;
+
+            return;
+        }
+
+        Result = sector;
+        _dialog.Close(true);
+    }
+
+    void Cancel()
+    {
+        Result = null;
+        _dialog.Close(false);
+    }
+}