Retain column width in QTableView

##### Orange version

3.36

##### Expected behavior
Remember column was resized in a data table and apply resizing on column width computation?

##### Actual behavior
I'd like to retain column width in data tables across Orange. For example, I open Data Table and resize one text column. Now, I change something upstream. The data table is updated and column resized to default. If I wish to interactively observe changes to my workflow, I have to keep resizing the column to the desired width.

##### Steps to reproduce the behavior
Corpus (deerwester) - Statistics - Data Table. Resize column in Data Table, recompute statistics.

##### Additional info (worksheets, data, screenshots, ...)
This might be a pain in the butt to do. Or not. I rely on experts (@ales-erjavec) to decide whether this is a doable solution.

Reproduce the workflow in Data Table using Corpus (deerwester) → Statistics → Data Table, then resize a text column and recompute Statistics. Inspect the Data Table update and QTableView column-width behavior. Done means a manually resized column retains its width after the data table is updated.

Written by the indexing model from the issue text.