Add FormDataEvent to externs
Add FormDataEvent to externs

TypeScript 4.4 added types for FormDataEvent (https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#the-formdataevent-interface) to its standard lib.dom.d.ts typings. This adds the same to the default JavaScript externs.

PiperOrigin-RevId: 397019935

google/closure-compiler,nawawi/closure-compiler,ChadKillingsworth/closure-compiler,ChadKillingsworth/closure-compiler,monetate/closure-compiler,monetate/closure-compiler,ChadKillingsworth/closure-compiler,nawawi/closure-compiler,monetate/closure-compiler,monetate/closure-compiler,google/closure-compiler,google/closure-compiler,nawawi/closure-compiler,nawawi/closure-compiler,google/closure-compiler,ChadKillingsworth/closure-compiler