[FancyZones] Restore size of zoned windows (#4463)

* Started work

* I can't debug anything, cleaning

* Added settings, [[Not Tested]]

Not even compiled

* Tested, the most basic features work

* Refactor, add RestoreSize

* Added DPI awareness

* Fixed a potential issue with resizing zoned windows

* Fixup: Potentially unsafe memory-layout of std::pair replaced with std::array

* Fixup: Use .data() instead of a pointer

* Further refactoring

* Integrated Win+Arrow keys with the Restore size feature

* Fixed an issue where window's on-screen position is not restored properly

* Fixed a bug pointed out by Enrico

src/core/Microsoft.PowerToys.Settings.UnitTest/ViewModelTests/FancyZones.cs

@@ -194,6 +194,24 @@ namespace ViewModelTests
             viewModel.AppLastZoneMoveWindows = true;
         }
 
+        [TestMethod]
+        public void RestoreSize_ShouldSetValue2True_WhenSuccessful()
+        {
+            // arrange
+            FancyZonesViewModel viewModel = new FancyZonesViewModel();
+            Assert.IsFalse(viewModel.RestoreSize); // check if value was initialized to false.
+
+            // Assert
+            ShellPage.DefaultSndMSGCallback = msg =>
+            {
+                FancyZonesSettingsIPCMessage snd = JsonSerializer.Deserialize<FancyZonesSettingsIPCMessage>(msg);
+                Assert.IsTrue(snd.Powertoys.FancyZones.Properties.FancyzonesRestoreSize.Value);
+            };
+
+            // act
+            viewModel.RestoreSize = true;
+        }
+
         [TestMethod]
         public void UseCursorPosEditorStartupScreen_ShouldSetValue2False_WhenSuccessful()
         {