[Common]NotificationUtil helper class with FileWatcher (#36720)

* add NotificationUtil helper with file watcher and cache

* fix spellcheck

* indentation

src/common/notifications/NotificationUtil.cpp

@@ -0,0 +1,56 @@
+#include "pch.h"
+#include "NotificationUtil.h"
+
+#include <common/notifications/notifications.h>
+#include <common/notifications/dont_show_again.h>
+#include <common/utils/resources.h>
+#include <common/SettingsAPI/settings_helpers.h>
+
+// Non-Localizable strings
+namespace NonLocalizable
+{
+    const wchar_t RunAsAdminInfoPage[] = L"https://aka.ms/powertoysDetectedElevatedHelp";
+    const wchar_t ToastNotificationButtonUrl[] = L"powertoys://cant_drag_elevated_disable/";
+}
+
+namespace notifications
+{
+    NotificationUtil::NotificationUtil()
+    {
+        ReadSettings();
+        auto settingsFileName = PTSettingsHelper::get_powertoys_general_save_file_location();
+
+        m_settingsFileWatcher = std::make_unique<FileWatcher>(settingsFileName, [this]() {
+            ReadSettings();
+        });
+    }
+
+    NotificationUtil::~NotificationUtil()
+    {
+        m_settingsFileWatcher.reset();
+    }
+
+    void NotificationUtil::WarnIfElevationIsRequired(std::wstring title, std::wstring message, std::wstring button1, std::wstring button2)
+    {
+        if (m_warningsElevatedApps && !m_warningShown && !is_toast_disabled(ElevatedDontShowAgainRegistryPath, ElevatedDisableIntervalInDays))
+        {
+            std::vector<action_t> actions = {
+                link_button{ button1, NonLocalizable::RunAsAdminInfoPage },
+                link_button{ button2, NonLocalizable::ToastNotificationButtonUrl }
+            };
+
+            show_toast_with_activations(message,
+                                        title,
+                                        {},
+                                        std::move(actions));
+
+            m_warningShown = true;
+        }
+    }
+
+    void NotificationUtil::ReadSettings()
+    {
+        auto settings = PTSettingsHelper::load_general_settings();
+        m_warningsElevatedApps = settings.GetNamedBoolean(L"enable_warnings_elevated_apps", true);
+    }
+}