Local Storage with multiple Miradors

[azaroth42]

The local storage of the display layout is only at the site/domain level, not individual mirador instance. So with multiple miradors, perhaps some private and some not, going from one to the other will bring the saved layout along unexpectedly.

Could also result in failures, when one mirador is in a password protected area, and another is not, and hence the credentials needed to retrieve manifest/image would not be available.