subscribeAutoScaleChange or subscribeAxisDblClick

[louisnw01]

In the current state of the library, its almost impossible to have a single source of truth for the value of autoScale, as users are allowed to change this value (and quite rightly so!) by dragging the axis or double clicking the axis.

It would be very useful if we could have a handler for this:

const handleAutoScaleChange = (newValue: boolean) => {
    // hook this into whatever we need to
} 
chart.priceScale('right').subscribeAutoScaleChange(handleAutoScaleChange);

or

chart.priceScale('right').subscribeDblClick(handleAxisDoubleClick);

auto scaling is essentially a latch that disables itself whenever the user would like to. This is expected behaviour, but being able to hook into this behaviour would be very useful for many developers.

Thanks!