feat: export defaultAllowedOrigins for user-land config and 3rd party plugins (#19259)

Author: timacdonald

packages/vite/src/node/publicUtils.ts

@@ -9,6 +9,7 @@ export {
   DEFAULT_CLIENT_MAIN_FIELDS as defaultClientMainFields,
   DEFAULT_SERVER_CONDITIONS as defaultServerConditions,
   DEFAULT_SERVER_MAIN_FIELDS as defaultServerMainFields,
+  defaultAllowedOrigins,
 } from './constants'
 export { version as esbuildVersion } from 'esbuild'
 export {