Improve style setter property checks for CaretBrush/Foreground

Updated logic to compare dependency property objects directly
instead of using string property names when identifying and
manipulating CaretBrush and Foreground setters. This enhances
robustness and reduces risk of errors from string comparisons.

Author: Jack251970

Flow.Launcher.Core/Resource/Theme.cs

@@ -217,9 +217,9 @@ private static void SetFontProperties(Style style, FontFamily fontFamily, FontSt
                 style.Setters.Add(new Setter(Control.FontStretchProperty, fontStretch));
 
                 // Set caret brush (retain existing logic)
-                var caretBrushProperty = style.Setters.OfType<Setter>().Where(x => x.Property.Name == "CaretBrush")?
+                var caretBrushProperty = style.Setters.OfType<Setter>().Where(x => x.Property == TextBoxBase.CaretBrushProperty)?
                     .FirstOrDefault();
-                var foregroundPropertyValue = style.Setters.OfType<Setter>().Where(x => x.Property.Name == "Foreground")
+                var foregroundPropertyValue = style.Setters.OfType<Setter>().Where(x => x.Property == Control.ForegroundProperty)
                     .Select(x => x.Value).FirstOrDefault();
                 if (caretBrushProperty != null && foregroundPropertyValue != null)
                 {
@@ -245,6 +245,7 @@ private static void SetFontProperties(Style style, FontFamily fontFamily, FontSt
                     style.Setters.Remove(setter);
                 }
 
+                // Add New font setter
                 style.Setters.Add(new Setter(TextBlock.FontFamilyProperty, fontFamily));
                 style.Setters.Add(new Setter(TextBlock.FontStyleProperty, fontStyle));
                 style.Setters.Add(new Setter(TextBlock.FontWeightProperty, fontWeight));