Fixed collapsing of expandable row after starting to drag it in sortable table


Steps to reproduce issue:
1. Create a grid with expandable rows
2. Make the grid sortable using `sortableRows` functionality
3. Expand a row
4. Try to reorder rows using drag'n drop

EB: expanded content was hidden
AB: expanded content was not hidden, but row was marked as collapsed.

This check-in fixes this issue by adding IDs to row with expandable content and using these IDs for finding such rows (instead of `r = tr.nextSibling;` which is not working when `tr` is being dragged)