[Enhancement] Heart rate monitor: possibility to set measurement interval without interpolation

[petermolnar]

I've recently been diagnosed with an irregular heartbeat - something that messes up even high-end medical instrument interpolation. It would be really nice to have a heart rate monitor that shows the actual beats per measured time, or to set the measurement interval maybe even up to multiple minutes to get a better reading.

[LinuxinaBit]

There is a pr that should fix general heart-rate measurement first: #1486
I'm not even sure there is any interpolation, it's just all around bad as of now.