12759 panel header menu in React (standard options only)

Fix terms agg order deprecation warning on es 6+

Exporter bug fix 

fixed exporter bug missing adding requires for datasources only used via data source variable, fixes #13891

Merge branch 'export_dashboard_guidence' of https://github.com/bergquist/grafana into bergquist-export_dashboard_guidence

build: removes unused.

Fix typo in docs/sources/reference/scripting.md

Change:
> In the folder grafana install folder under `public/dashboards/` there is a file named `scripted.js`.
…to:
> In the grafana install folder under `public/dashboards/` there is a file named `scripted.js`.

wip: panel-header: Add "Edit JSON" functionality + make sure everyone using the json editor pass in the model property instead of the scope property when triggering the json modal

[skip ci]

[skip ci]