(listed-only) Addon reviewers don't see the "approval_notes" via addons api

[ioanarusiczki]

Followup #8835

STR:

1. As a reviewer with permissions (can review listed addons) make a request such as
   https://addons-dev.allizom.org/api/v5/addons/addon/622084/versions/1694723/ -> listed version, not public
   https://addons-dev.allizom.org/api/v5/addons/addon/622084/versions/1694724/ -> public listed version

Expected result:
"approval_notes" should be displayed in the JSON response.

Notes:
This is not reproducible for the unlisted reviewers.

┆Issue is synchronized with this Jira Task

[eviljeff]

listed reviewers are a bit of an edge case. For unlisted reviewers (and other admin-ish users) we can use the developer's serializer; for listed reviewers we can't. I'm not sure there is much of a use-case here as there are dedicated reviewer apis for code-manager etc, so it's unclear under what circumstances a listed reviewer would need such information via the general addons api.

[KevinMind]

Old Jira Ticket: https://mozilla-hub.atlassian.net/browse/ADDSRV-115