Add support for ddm and inventory for DES-1210-28/ME B3

Just copy includes/discovery/sensors/des-1210-28me-b2.inc.php to includes/discovery/sensors/des-1210-28me-b3.inc.php
and cope includes/discovery/inventory/des-1210-28me-b2.inc.php to includes/discovery/inventory/des-1210-28me-b3.inc.php

add some minor changes:

• comment with examples
• OID to another tree

  '.1.3.6.1.4.1.171.10.75.15.2.105.2.1.1.1.2.' . $index

  ->

  '.1.3.6.1.4.1.171.10.75.15.3.105.2.1.1.1.2.' . $index

  ^

related to OBS-4324