Filter by reduction over time

<!-- Please only use this template for submitting feature requests --> **Why is this needed**: In this specific case I have a dashboard which monitors statuses of different systems and system utilization by different processes and/or users. As it is, some of these panels become very cluttered by low utilization processes or similar. Especially the legend but also to the timeseries graphs themselves. I would rather just see the timeseries that might be of interest based on some summary statistic of each timeseries (max, sum or similar). I could filter each datapoint on some threshold with a binary greater then, but this doesn't really help for small thresholds and for large thresholds it removes information that can be of interest for the timeseries of interest. **What would you like to be added**: Either a transform or an operation that filters an entire timeseries/set-of-labels based on some reduction over time. Something like: `Filter by reduction over time: <Reduction drop down>, <binary relation drop down, i.e. greater than etc.> <threshold value entry>` **Who is this feature for?** Anyone who doesn't want this clutter in their panels. For example koshmariel here https://community.grafana.com/t/filter-series-in-a-time-series-graph/64218