[RFC] View-specific localStorage settings API

[NoahBres]

• API for Dash views to have persistent settings for each view
• Views are already assigned unique and persistent ID's in the ConfigurableLayout view
• Default layouts need to assign Views ID's.
• Have a consistent interface so views can store settings in local storage
• This is necessary so ConfigurableLayout can delete View settings from local storage when views are deleted from the layout
• Further elaboration in the upcoming custom field image PR

Design + requested commentary in progress