Fixed Label Visibility Issue on macOS and iOS (#28081)

* Fixed Label Display on macOS and IOS When Padding is Applied

* Optimized the fix

* Added test case

* Added Snapshot for android and iOS

* Added snapshot for winUI and macOS, updated test sample

Author: Dhivya-SF4094

src/Controls/tests/TestCases.Android.Tests/snapshots/android/LabelWithPadding.png

@@ -0,0 +1,27 @@
+namespace Maui.Controls.Sample.Issues
+{
+    [Issue(IssueTracker.Github, 19007, "Incomplete Label Display on macOS and IOS When Padding is Applied", PlatformAffected.iOS)]
+    public class Issue19007 : ContentPage
+    {
+        public Issue19007()
+        {
+            var grid = new Grid();
+            grid.RowDefinitions.Add(new RowDefinition { Height = GridLength.Auto });
+            grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(100) });
+
+            var label = new Label
+            {
+                Background = Colors.Red,
+                Text = ".NET Multi-platform App UI (.NET MAUI) is a cross-platform framework for creating mobile and desktop apps with C# and XAML.",
+                Padding = new Thickness(20),
+                AutomationId = "Label"
+            };
+
+            grid.Children.Add(label);
+            Grid.SetRow(label, 0);
+            Grid.SetColumn(label, 0);
+
+            Content = grid;
+        }
+    }
+}

src/Controls/tests/TestCases.HostApp/Issues/Issue19007.cs

@@ -0,0 +1,21 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+public class Issue19007 : _IssuesUITest
+{
+    public Issue19007(TestDevice testDevice) : base(testDevice)
+    {
+    }
+
+    public override string Issue => "Incomplete Label Display on macOS and IOS When Padding is Applied";
+
+    [Test]
+    [Category(UITestCategories.Label)]
+    public void LabelWithPadding()
+    {
+        App.WaitForElement("Label");
+        VerifyScreenshot();
+    }
+}

src/Controls/tests/TestCases.Mac.Tests/snapshots/mac/LabelWithPadding.png

@@ -68,7 +68,10 @@ RectangleF AlignVertical(RectangleF rect)
 
 		public override SizeF SizeThatFits(SizeF size)
 		{
-			var requestedSize = base.SizeThatFits(size);
+			// Prior to calculating the text size, reduce the padding, and then add the padding back in the AddInsets method.
+			var adjustedWidth = size.Width - TextInsets.Left - TextInsets.Right;
+			var adjustedHeight = size.Height - TextInsets.Top - TextInsets.Bottom;
+			var requestedSize = base.SizeThatFits(new SizeF(adjustedWidth, adjustedHeight));
 
 			// Let's be sure the label is not larger than the container
 			return AddInsets(new Size()