Exported API for `/api/packages/<package>/*`

[jonasfj]

Let's do exported API for all GET requests for:

/api/packages/<package>/likes
/api/packages/<package>/metrics
/api/packages/<package>/options
/api/packages/<package>/publisher
/api/packages/<package>/score
/api/packages/<package>/versions/<version>/options
/api/packages/<package>/versions/<version>/score