dbconsole: add link to events in left sidebar

Currently, the `/events` endpoint can only be reached by navigating to the metrics > "view all events" link in the 'events' pane.

It would be great if we could:
- put a link to the events page in the left sidebar, say between Jobs and Schedules.
- improve the page by using a table to filter, sort and search the various events.
- review what constitutes a valuable event: node rejoining, DDL changes, cluster setting changes, etc.

[slack](https://cockroachlabs.slack.com/archives/C063CP41TG9/p1703171037793839)

Jira issue: CRDB-34873

Start with the dbconsole left sidebar and the existing /events page reached through Metrics > "View all events". Define the sidebar placement, table filtering and sorting behavior, and which events are valuable, then verify that the page is reachable from the sidebar and supports the agreed event review.

Written by the indexing model from the issue text.