ability to conditionally format columns if editing is disabled [Sponsored: Due May 1]

[chriddyp]

Enable Dash developers to update the style depending on whether the column is editable or not.
This would likely be an additional option in our style_data_conditional property (see e.g. https://dash.plot.ly/datatable/style)

[Marc-Andre-Rivet]

All style_**_conditional to get an additional is_editable: boolean nested prop inside the if.

For each, we need to modify the calculation pipeline to take the new condition into consideration.
Have a look at dash-table/derived/style/index.ts to see how it all glues together.

[alexcjohnson]

Closed by #462