[APM] Fix legacy routing to prevent full page refresh between Observability apps

[ogupte]

Navigating away from APM using Actions menu causes a full page refresh. As noted in #64046, we have not yet changed the routing history scheme, so some navigations between observability apps cause a full page refresh.

Clicking on the icons in the sidebar for Metrics or Logs will navigate to those apps without a full page refresh, but if you're looking at a transaction and use the Actions menu to navigate to a link like "Host Logs", "Host Metrics", or anything that uses /app/logs/link-to or /app/metrics/link-to you'll get a full page refresh and the Kibana loading spinner.

Following links to any NP app from APM should not cause a full page refresh.

It would also allow us to use routes without hashes in the URL. We may need to add redirects from the older hash-based routes to new routes so that users' bookmarks and links are not broken.