Syncing multiple charts' viewports

It is reasonably common to want to have multiple charts "synced" when panning/zooming. An example is to plot yaw, pitch and roll against time on three separate graphs. If the user zooms in on the yaw graph, the pitch and roll graphs should zoom in the same manner.

Currently it is technically possible, but difficult. We should develop an API to make this simple, perhaps something like:
```
rollChart.syncViewPort(to: yawChart)
pitchChart.syncViewPort(to: rollChart)
```

This is a feature that would also need an Android implementation @PhilJay.

Start by tracing the existing iOS viewport, panning, and zooming behavior, then identify the corresponding Android implementation. Define and validate a cross-chart synchronization API so separate yaw, pitch, and roll charts pan and zoom together on both platforms.

Written by the indexing model from the issue text.