history chart: enable dynamic zoom on both axis.

[poulanker]

It is a nice feature that one can now dynamically zoom the x-axis to view details on the timeline.
However, the initial resolution on the y-axis depends on the largest value within the time span, which idefaults to one day. Unfortunately the y-axis resolution cannot be changed when zooming dynamically.
I am aware that I can just change the start and end time (as we used to before dynamic zoom was implemented).

As an example I have an entity that measures total power consumption in the kitchen, but every half hour a heating element in a "Quooker" device, turns on for a minute and draws 2 kW. This makes it difficult to see the power fluctuation caused by other power consumers because the y-axis is linear and max value is 2000 W.

In the time of this writing, we use the Scroll Wheel while holding down the Ctrl-key on the keyboard to zoom in or out on the x-axis.
I would like to suggest that a feature is added, that dynamically zooms the y-axis when both the Ctrl-key and Shift-key are held down.
On a phone or tablet this would be analogue to mowing two fingers opposite on the y-axis.