Attachments Rework

[luis-camero]

Requires: lcamero/attachments in clearpath_common: https://github.com/clearpathrobotics/clearpath_common/tree/lcamero/attachments

Standardized attachment, these now have the following parameters:

• name: [required] the name of the link of the attachment that is to be added. i.e. top_plate -> top_plate_link
• type: [required] the type of attachment; these are the top level of attachment categories. i.e. `fender', 'bumper', 'top_plate'
• model: the subtype of attachment, these would be the model of the type, i.e. the model pacs of the type top_plate
• parent: the parent link of the attachment. the default is set to the default position of the type.

  This will need more work because it requires all robots to have the same parent links. For example, mid_mount should exist in all of the platforms (including generic ones).

• xyz and rpy to move the attachments around.

  Note: without the mid_mount on the Husky, we are unable to move the top plate using xyz and rpy, so although multiple can be added, they would all be in the same place.

[roni-kreinin]

@luis-camero Can you add some more W200 samples?

[luis-camero]

Added a Dual Hokuyo and a Single Tower with Velodyne samples for the W200.