Preserve latest map extent in Space Planner plans

[RegenaOttaviano]

It would be helpful if plans in Space Planner preserved their last viewed extent.

This would allow reviewers to open a plan and immediately see where updates were made, rather than defaulting to the configured web map extent and requiring manual navigation to areas of interest.

[AaronKoelker]

Agree, and for a related use case—we have Space Planner users who focus on different sites/facilities. Some would like the default extent to be in one spot while others want another spot.  Remembering last extent would be nice, but if a default extent could be set and stored at a Plan level, rather than always referencing the web map item default, that would be a great improvement too.