Add filter for time column

[gaetronik]

First of all, thanks for this great software
I may have missed how to do so in the documentation but I would like to be able to filter process given a threshold of time.
For instance procs --filter ElapsedTime GreaterThan 1h --and my_proc to list all process older than 1h named my_proc.
It would make the search of stuck process easier than doing so with --sortd

[timuric]

somehow related issue #510

[gaetan-craft]

In fact #510 will be enough for my use case