[Backport 2.x] Reverting notebooks changes, add docs/validation to datasources, explorer minor fixes#1102

ps48 merged 1 commit into2.xopensearch-project/dashboards-observability:2.xfrom

backport/backport-1101-to-2.xopensearch-project/dashboards-observability:backport/backport-1101-to-2.xCopy head branch name to clipboard