use simple_event schema to track iframe card creation (#48739) (#48750)

e2e/test/scenarios/dashboard/dashboard.cy.spec.js

frontend/src/metabase-types/analytics/dashboard.ts

frontend/src/metabase-types/analytics/event.ts

frontend/src/metabase/dashboard/analytics.ts

frontend/src/metabase/lib/analytics.ts

...-embedded/schemas/com.metabase/dashboard/jsonschema/1-1-6