This will make it easier to tie an SSH access request to Rails API and
Gitaly requests.

Right now when a client such as gitlab-shell calls the
`/api/v4/internal/allowed` API, the response only tells the client what
user has been granted access, and it's impossible to tell which deploy
key/token was used in the authentication request.

This commit adds logs for the following when available:

1. `gl_key_type` (e.g. `deploy_key` or `key`)
2. `gl_key_id`

These fields make it possible for admins to identify the exact record
that was used to authenticate the user.

API changes in the `/internal/allowed` endpoint in
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/37289 are needed
to support this.

Relates to https://gitlab.com/gitlab-org/gitlab-shell/-/issues/203

Calling logrus hook.LastEntry() can lead to race conditions.  Use
AllEntries instead:
https://github.com/sirupsen/logrus/blob/60c74ad9be0d874af0ab0daef6ab07c5c5911f0d/hooks/test/test.go#L77

Closes https://gitlab.com/gitlab-org/gitlab-shell/-/issues/450