Service account access tokens need to be added to Credentials Inventory on GitLab.com & SM versions

Original Issue

PAT or other types tokens can be generated for Service accounts, these should be listed in the Credential Manager available on self managed instances of GitLab but are not currently displayed. We should update the user query on the page to include service account acacess tokens in the list

Summary

PAT or other types tokens can be generated for Service accounts, these should be listed in the Credential Manager available on self managed instances of GitLab but are not currently displayed and on GitLab.com variant of Credentials Inventory.

Additionally we should also add a filter to be able to easily view service account PATs between human account associated ones.