Subviews and frozen columns scroll issue

First, thanks for this excellent framework! no words can describe how great it is, and how much work it saved me!

I would like to have an overlay view, I'm doing it using the info from this related merged fix:
https://github.com/bannzai/SpreadsheetView/issues/33
https://github.com/bannzai/SpreadsheetView/pull/57

Please see the red vertical overlay view in this screenshot:


The issue is when scrolling I would like it to go below the frozen green column, can it be done using existing code, or the only way is to add this feature to the framework?


Thanks!

## Expected Behavior
When adding a subview using ```spreadsheet.addSubview(myView)``` and having also a frozen column, the subview should scroll below the frozen column

## Actual Behavior
the subview scrolls to the left and appears above the frozen column

## Steps to Reproduce the Problem
1. Add a spreadsheet with 1 frozen column
2. Add normal rows and columns to the sheet
3. Add a subview to the sheet, which internally is added to the overlayView
4. Scroll the content

## Specifications

- Xcode version: 12
- iOS version: 14
- Dependency manager + version: Cocoapods 10