Mount message dialogs once at the list level (#10435)

Co-authored-by: Samuel Newman <mozzius@protonmail.com>

src/components/moderation/ReportDialog/index.tsx

@@ -75,9 +75,11 @@ export function ReportDialog(
     () => (props.subject ? parseReportSubject(props.subject) : undefined),
     [props.subject],
   )
+  const propsOnClose = props.onClose
   const onClose = useCallback(() => {
     ax.metric('reportDialog:close', {})
-  }, [ax])
+    propsOnClose?.()
+  }, [ax, propsOnClose])
   return (
     <Dialog.Outer control={props.control} onClose={onClose}>
       <Dialog.Handle />

src/components/moderation/ReportDialog/types.ts

@@ -88,4 +88,8 @@ export type ReportDialogProps = {
    * Called if the report was successfully submitted.
    */
   onAfterSubmit?: () => void
+  /**
+   * Called after the dialog finishes closing.
+   */
+  onClose?: () => void
 }