DOCSP-49217: disable id alias conversion in embedded docs

[rustagir]

https://jira.mongodb.org/browse/DOCSP-49217

Adds documentation about disabling id -> _id conversion in embedded fields.

STAGING

cross links:
QB page
Upgrade page

Checklist

• Add tests and ensure they pass

[GromNaN]

There is 2 ways of setting the configuration:

• in config/database.php, using 'rename_embedded_id_field' => false
• anywhere in the code, using DB::connection('mongodb')->setRenameEmbeddedIdField(false);