Add hovered-on scroll bar button textures

Co-authored-by: Bittah Commander <7165430+Bittah@users.noreply.github.com>

Author: Rampastring

src/TSMapEditor/Content/sbDownArrowHovered.png

@@ -375,6 +375,9 @@
     <None Update="Content\sbDownArrow.png">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
+    <None Update="Content\sbDownArrowHovered.png">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
     <None Update="Content\sbMiddle.png">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
@@ -387,6 +390,9 @@
     <None Update="Content\sbUpArrow.png">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
+    <None Update="Content\sbUpArrowHovered.png">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
     <None Update="Content\sortbutton.png">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>