Add a success dialog to window renaming (#9808)

I added a `RenameSucceededText` property to the `TerminalPage` which returns the
formatted message `Successfully renamed window to "{WindowNameForDisplay()}"`

This _doesn't_ pop the dialog when you `wt -w foo` for the first time. Only
_subsequent_ renames.

## References
* Added in #9662
* Closes #9804

src/cascadia/TerminalApp/TerminalPage.cpp

@@ -2607,12 +2607,32 @@ namespace winrt::TerminalApp::implementation
     {
         return _WindowName;
     }
-    void TerminalPage::WindowName(const winrt::hstring& value)
+
+    winrt::fire_and_forget TerminalPage::WindowName(const winrt::hstring& value)
     {
-        if (_WindowName != value)
+        const bool changed = _WindowName != value;
+        if (changed)
         {
             _WindowName = value;
-            _PropertyChangedHandlers(*this, WUX::Data::PropertyChangedEventArgs{ L"WindowNameForDisplay" });
+        }
+        auto weakThis{ get_weak() };
+        // On the foreground thread, raise property changed notifications, and
+        // display the success toast.
+        co_await resume_foreground(Dispatcher());
+        if (auto page{ weakThis.get() })
+        {
+            if (changed)
+            {
+                page->_PropertyChangedHandlers(*this, WUX::Data::PropertyChangedEventArgs{ L"WindowName" });
+                page->_PropertyChangedHandlers(*this, WUX::Data::PropertyChangedEventArgs{ L"WindowNameForDisplay" });
+
+                // DON'T display the confirmation if this is the name we were
+                // given on startup!
+                if (page->_startupState == StartupState::Initialized)
+                {
+                    page->IdentifyWindow();
+                }
+            }
         }
     }
 

src/cascadia/TerminalApp/TerminalPage.h

@@ -102,7 +102,7 @@ namespace winrt::TerminalApp::implementation
         // WINRT_OBSERVABLE_PROPERTY's, but we want them to raise
         // WindowNameForDisplay and WindowIdForDisplay instead
         winrt::hstring WindowName() const noexcept;
-        void WindowName(const winrt::hstring& value);
+        winrt::fire_and_forget WindowName(const winrt::hstring& value);
         uint64_t WindowId() const noexcept;
         void WindowId(const uint64_t& value);
         winrt::hstring WindowIdForDisplay() const noexcept;