feat(discover): Add serializer for discover endpoint (#8816)
feat(discover): Add serializer for discover endpoint (#8816)

Moves validation into a serializer, follow up to #8759

looker/sentry,mvaled/sentry,mvaled/sentry,mvaled/sentry,mvaled/sentry,mvaled/sentry,ifduyue/sentry,mvaled/sentry,ifduyue/sentry,beeftornado/sentry,looker/sentry,looker/sentry,beeftornado/sentry,ifduyue/sentry,ifduyue/sentry,beeftornado/sentry,looker/sentry,looker/sentry,ifduyue/sentry