make v1->v3 upgrade work with --features=bundled

--features=bundled enables -DSQLITE_DEFAULT_FOREIGN_KEYS=1, and so some
operations have to be done in the proper order.

* enable foreign key enforcement all the time, so I test this more reliably.
* reorder some parts of the v1->v3 order. foreign key enforcement is
  immediate (rather than deferred) by default. and ensure
  old_recording_playback isn't left with a dangling reference to old_recording
  at the v2 stage. Instead, wait until v3 to delete tables it depends on.

db/upgrade/v2_to_v3.rs

@@ -114,6 +114,9 @@ pub fn run(_args: &super::Args, tx: &rusqlite::Transaction) -> Result<(), Error>
         from
           old_recording_playback;
         drop table old_recording_playback;
+        drop table old_recording;
+        drop table old_camera;
+        drop table old_video_sample_entry;
     "#)?;
     Ok(())
 }