refactor(emails): fold registry into newspack_email_configs schema (NPPD-1550)#4762

kmwilkerson wants to merge 9 commits into

nppd-945-unified-emails-newspack-sliceAutomattic/newspack-plugin:nppd-945-unified-emails-newspack-slicefrom

nppd-1550-refactor-fold-email-registry-into-newspack_email_configsAutomattic/newspack-plugin:nppd-1550-refactor-fold-email-registry-into-newspack_email_configsCopy head branch name to clipboard