Display 'Average Time' as a column similar to 'Total Time'

[m4mukulgarg]

Is your feature request related to a problem? Please describe.
I have to mentally calculate the average time for each thread/query executed

Describe the solution you'd like
A new column in the profiling results tab where I can see the average time (calculated as total_time/invocations) is displayed for each row

Describe alternatives you've considered
Mentally calculating the results.

Additional context

[thurka]

Done in master. New 'Average Time' column was added. It is hidden by default.