TextStatsPlots.show_stats() should call TextStatsPlots.return_stats()

[meghdadFar]

Improvement:TextStatsPlots.show_stats() should call TextStatsPlots.return_stats()

Description:

We have created a new function TextStatsPlots.return_stats() for Datachat. It does most of what is done inside TextStatsPlots.show_stats() but instead of printing the stats in a tabulate table, it returns a json. The goal of this issue is to update TextStatsPlots.show_stats() so that it calls TextStatsPlots.return_stats() and then properly format the return value in a list so that it can be passed to tabulate. This will improve the consistency and allows us to get the stats only in one place i.e. TextStatsPlots.return_stats().