Combine Navigation for Frontend and Backend pages into Snowplow

Jerome Z Ngrequested to merge
jeromezng-master-patch-76022 into master

This MR is a continuation of gitlab!28630 (merged). This MR combines the navigation under Telemetry from Frontend and Backend to Snowplow.

Parent issue: https://gitlab.com/gitlab-org/telemetry/issues/290

Edited by Jerome Z Ng

Merge request reports