Selectable, MenuItem: don't use frame rounding for hovering/selection.

imgui.cpp

@@ -7451,7 +7451,7 @@ static bool SelectableEx(const char* label, bool selected, const ImVec2& size_ar
     if (hovered || selected)
     {
         const ImU32 col = window->Color((held && hovered) ? ImGuiCol_HeaderActive : hovered ? ImGuiCol_HeaderHovered : ImGuiCol_Header);
-        RenderFrame(bb_with_spacing.Min, bb_with_spacing.Max, col, false, style.FrameRounding);
+        RenderFrame(bb_with_spacing.Min, bb_with_spacing.Max, col, false, 0.0f);
     }
     if (flags & ImGuiSelectableFlags_Disabled) ImGui::PushStyleColor(ImGuiCol_Text, g.Style.Colors[ImGuiCol_TextDisabled]);
     RenderTextClipped(bb.Min, bb_with_spacing.Max, label, NULL, &label_size);