Scrolling "out of range" data should be enabled - optionally

[leonbloy]

Summary

Currently we can zoom out but we cannot scroll (pan) outside the provided data range.
But that is needed when doing lazy/on-demand data loading.

API Changes

Perhaps a new option inside { chart : { zoom : { allowOutOfRange: false } ...

Intended Use Case

When the data is not available in full, but is obtained on demand (subscribing to the zoomed and scrolled events), zooming and panning freely is essential. Currently we can do that only by zooming out (which is itself inconsistent: why would Apex allow us to zoom out of range and not scroll?).

Notice that in other scenarios this behaviour is not desired, so this should be an option
See eg #3603
(not sure about the default).