Add Family size table watching

[SergeyNefyodov]

Summary of the Pull Request

What is this about:

I added a possibility to watch read-only FamilySizeTable by clicking context menu, using dialogs

Quality Checklist

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings

[Nice3point]

@SergeyNefyodov I've cleaned the code a bit on the comments above, it looks like: Compare with before:

Maybe the drawback is the Column1 name for the first column, but DataTable doesn't support empty name