Bake setup step logic into the view models themselves instead of being in the setup wizard implementation

renamed view models to contexts (like TKMM), however the contexts here are actually of a unique base type; containing aforementioned setup step logic. if the return value is of an error state result, it will prompt a retry of the page.

src/Ryujinx/UI/SetupWizard/Pages/SetupFirmwarePageContext.cs

@@ -0,0 +1,122 @@
+using Avalonia.Controls;
+using Avalonia.Platform.Storage;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using Gommon;
+using Ryujinx.Ava.Common.Locale;
+using Ryujinx.Ava.Systems.SetupWizard;
+using Ryujinx.Ava.UI.Helpers;
+using Ryujinx.Ava.Utilities;
+using Ryujinx.Common.Configuration;
+using Ryujinx.HLE.FileSystem;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+
+namespace Ryujinx.Ava.UI.SetupWizard.Pages
+{
+    public partial class SetupFirmwarePageContext : SetupWizardPageContext
+    {
+        [ObservableProperty]
+        public partial string FirmwareSourcePath { get; set; }
+
+        [RelayCommand]
+        private static async Task BrowseFile(TextBox tb)
+        {
+            Optional<IStorageFile> result = await RyujinxApp.MainWindow.ViewModel.StorageProvider.OpenSingleFilePickerAsync(new FilePickerOpenOptions
+            {
+                Title = LocaleManager.Instance[LocaleKeys.SetupWizardFirmwarePageFilePopupTitle],
+                FileTypeFilter = new List<FilePickerFileType>
+                {
+                    new(LocaleManager.Instance[LocaleKeys.FileDialogAllTypes])
+                    {
+                        Patterns = ["*.xci", "*.zip"],
+                        AppleUniformTypeIdentifiers = ["com.ryujinx.xci", "public.zip-archive"],
+                        MimeTypes = ["application/x-nx-xci", "application/zip"],
+                    },
+                    new("XCI")
+                    {
+                        Patterns = ["*.xci"],
+                        AppleUniformTypeIdentifiers = ["com.ryujinx.xci"],
+                        MimeTypes = ["application/x-nx-xci"],
+                    },
+                    new("ZIP")
+                    {
+                        Patterns = ["*.zip"],
+                        AppleUniformTypeIdentifiers = ["public.zip-archive"],
+                        MimeTypes = ["application/zip"],
+                    }
+                }
+            });
+
+            if (result.TryGet(out IStorageFile firmwareFile)) 
+            {
+                tb.Text = firmwareFile.TryGetLocalPath();
+            }
+        }
+
+        [RelayCommand]
+        private static async Task BrowseFolder(TextBox tb)
+        {
+            Optional<IStorageFolder> result = await RyujinxApp.MainWindow.ViewModel.StorageProvider.OpenSingleFolderPickerAsync(new FolderPickerOpenOptions 
+            {
+                Title = LocaleManager.Instance[LocaleKeys.SetupWizardFirmwarePageFolderPopupTitle]
+            });
+
+            if (result.TryGet(out IStorageFolder firmwareFolder)) 
+            {
+                tb.Text = firmwareFolder.TryGetLocalPath();
+            }
+        }
+
+        public override Result CompleteStep()
+        {
+            if (!Directory.Exists(FirmwareSourcePath))
+                return Result.Fail;
+
+            try
+            {
+                RyujinxApp.MainWindow.ContentManager.InstallFirmware(FirmwareSourcePath);
+                SystemVersion installedFwVer = RyujinxApp.MainWindow.ContentManager.GetCurrentFirmwareVersion();
+                if (installedFwVer != null)
+                {
+                    NotificationHelper.ShowInformation(
+                        "Firmware installed",
+                        $"Installed firmware version {installedFwVer.VersionString}."
+                    );
+                }
+                else
+                {
+                    NotificationHelper.ShowError(
+                        "Firmware not installed",
+                        $"It seems some error occurred when trying to install the firmware at path '{FirmwareSourcePath}'." +
+                        "\nDid that folder contain a firmware dump?"
+                    );
+                }
+                RyujinxApp.MainWindow.ViewModel.RefreshFirmwareStatus(installedFwVer, allowNullVersion: true);
+
+                if (installedFwVer is null)
+                    return Result.Fail;
+
+                // Purge Applet Cache.
+
+                DirectoryInfo miiEditorCacheFolder = new(
+                    Path.Combine(AppDataManager.GamesDirPath, "0100000000001009", "cache")
+                );
+
+                if (miiEditorCacheFolder.Exists)
+                {
+                    miiEditorCacheFolder.Delete(true);
+                }
+            }
+            catch (Exception e)
+            {
+                NotificationHelper.ShowError(e.Message, waitingExit: true);
+                return Result.Fail;
+            }
+
+            return Result.Success;
+        }
+    }
+}