Copy file attachment edges to new storage

Summary: Ref T13603. Copy all existing file attachment data into the new storage table.

Test Plan: Ran migration, checked attachment table for general reasonableness.

Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam

Maniphest Tasks: T13603

Differential Revision: https://secure.phabricator.com/D21818

Author: epriestley

resources/sql/autopatches/20220519.file.02.migrate.sql

@@ -0,0 +1,7 @@
+INSERT IGNORE INTO {$NAMESPACE}_file.file_attachment
+  (objectPHID, filePHID, attachmentMode, attacherPHID,
+    dateCreated, dateModified)
+  SELECT dst, src, 'attach', null, dateCreated, dateCreated
+    FROM {$NAMESPACE}_file.edge
+    WHERE type = 26
+    ORDER BY dateCreated ASC;