Edit in Grid
In WPF, grid cells are editable whenever the ReadOnlyExpression does not evaluate to false.
In AngularJS, grid cells are editable only when given a tagged value Editable=true.
The tagged value is set on the Nesting that holds the grid columns; grid columns then adhere to the ReadOnlyExpression.

Versions after 2022-05-02: You can now add a column <Name>_ReadOnly to enable cell-level read-only control for cells.
Currently, this cell level is only available in AngularJS editable grids.
