Add ModifySolidBrush method to update formatted text

A new `ModifySolidBrush()` method was introduced in the `Editor` namespace within `StaticText.cs`. This method updates the `_formattedTextExtended` object by invoking `FontFactory.GetFormattedTextExtended()` with parameters including `Text`, `FontType`, `FontSize` scaled by `FontSizeFactor`, `FontWeight`, and a `false` value for the last argument.

Author: Jack251970

Editor/Equations/Common/StaticText.cs

@@ -27,6 +27,11 @@ public override void DrawEquation(DrawingContext dc, bool forceBlackBrush)
             _formattedTextExtended.DrawTextTopLeftAligned(dc, new Point(Left + LeftMarginFactor * FontSize, Top + TopOffestFactor * Height), forceBlackBrush);
         }
 
+        public override void ModifySolidBrush()
+        {
+            _formattedTextExtended = FontFactory.GetFormattedTextExtended(Text, FontType, FontSize * FontSizeFactor, FontWeight, false);
+        }
+
         public override double FontSize
         {
             get => base.FontSize;