Layout Grid: Can't interact with a grid with nested grids

[enejb]

Describe the bug
Nesting the grid block within the grid doesn't work.

To Reproduce
Steps to reproduce the behaviour:

1. Add a Layout grid-block
2. Select a Column
3. Insert a Layout-grid in the column
4. Notice that you can't select the nested layout grid items.

Expected behaviour
Be able to nest the layout grid within the layout grid block
Or prevent the user from adding the layout grid inside a layout grid.

Screenshots

Screen.Recording.2021-06-01.at.3.40.59.PM.mov

Smartphone (please complete the following information):

• Device: All
• Version N/A

Additional context
This issue was opened to track bugs sound during testing of #3513