Add new approved Code Insights dashboard FE ping-actions

[vovakulikov]

Part of https://github.com/sourcegraph/sourcegraph/issues/27214

List of FE ping-actions to add

• number of unique dashboard editors per week (editors have created/deleted a dashboard, added/removed insights to a dashboard, or renamed a dashboard)
• number of unique first-time dashboard editors (by week)
• number of unique first-time dashboard creators (by week)
• number of unique dashboards viewed by at least 1 user that week

[github-actions]

Heads up @Joelkw @felixfbecker @vovakulikov @unclejustin - the "team/code-insights" label was applied to this issue.