Map Visualization: have "lock" option to synchronize viewport position for all splits

[rcrezende]

Let's say more than one map is shown using split columns/rows feature.
Would be great to have an option on the map panel that allows to lock two or more split maps. So if we explore one region in a split, it shows the same position in the other positions selected allowing comparison.

[LeeDr]

The ability to split Tile Maps is being removed in a future 5.0 release. See #6001

In light of that, I don't think it makes sense to keep this open. Please speak up if there's some significant use case we're breaking.

[nreese]

What about a wider use case where a dashboard contains multiple tile map visualizations. It would be nice to have a dashboard option to toggle on/off map synchronization.

Nathan