Add Export/Import Functionality for Dashboard States

[nicovon24]

Currently, in ThingsBoard, it is not possible to export and import dashboard states directly. This means that when I need to transfer a dashboard state to another dashboard, I have to manually export all widgets and then recreate a new dashboard state on the target dashboard. This process is really time-consuming, taking approximately 10 to 15 minutes each time I need to do it. I suggest adding the ability to export and import dashboard states directly, similar to the existing functionality for exporting and importing dashboards and rule chains.

Example:

• Dashboard 1:

have a button for downloading

• Dashboard 2:

And here the possibility to import dashboard states, currently there is possibility only to create one not to import it