Add Service Ping for Zoekt code search

We currently track the usage for Advanced Search, for example the search count, search count from the command palette(navbar), etc. As we roll out the Zoekt, we need to track the usage for Zoekt code search. It would be great to know the adoption from self-managed customers.

Example code of getting the information for advanced search, https://gitlab.com/gitlab-org/gitlab/-/blob/d7acf7c3d5d4eeb20abac83ce27732a12d7902a3/ee/app/controllers/ee/search_controller.rb#L19-24

Note

Zoekt now uses a GraphQL endpoint, so we'll need to add it on the API level instead of a search controller

Edited by Dmitry Gruzd