Show applied filters in the title bar of the processes widget

Checklist

• I've looked through the documentation and existing open issues for similar feature requests.

Describe the feature request

Bottom could show the filter phrase of applied filters behind the "Processes" title at the top, like "Processes - Filter: user=foo", so one could see it, when there's a filter applied. It's done like that in the CPU graph for CPU time values, so it would just be consistent to do the same for process filters.

[ClementTsang]

I'm not entirely convinced of doing this anytime soon; the search bar could just be left open, no? The only benefit I could see is that you save the vertical space occupied by the search bar.

It's done like that in the CPU graph for CPU time values, so it would just be consistent to do the same for process filters.

I really don't think you can equate the two...

That said, I might look at doing this in the future... but if anyone wants to take a swing at it first, feel free, it should be simple in terms of implementation.