data table sorting really slow with large data file

[anupparikh]

accidentally hit the column header which triggered a sort. Had to force quite the whole applications because sorting 20K rows was taking way too long.

trying loading the Rui Chen BCM files to reproduce.

[astaric]

Might already be fixed in current Orange master. (see biolab/orange3#2905)

[BlazZupan]

The issue was solved in Orange release 3.11. We will use this version of Orange in our next release of scOrange.