codec-socks test cleanup

Motivation:

The unit tests in codec-socks contained redundant casts and empty test classes.

Modifications:

- Remove redundant casts
- Delete empty test classes

Result:

Cleanup
[#2586] Use correct EventExecutor to notify for bind failures on late registration

Motivation:

We used the wrong EventExecutor to notify for bind failures if a late registration was done.

Modifications:

Use the correct EventExecutor to notify and only use the GlobelEventExecutor if the registration fails itself.

Result:

The correct Thread will do the notification.