[Manipulation] Run pick state machine in simulation

[deebuls]

Is your feature request related to a problem? Please describe. Run pick_object_server in simulation to pick an object

[sthoduka]

Currently it is not possible to run the pick_object_server SM without having perceived the workstation, since the object_selector is triggered from the pick server. The options are:

1. Get perceive_location action running in simulation
2. Temporarily create a mockup perceive_location action, which will get the objects' positions from gazebo.

I haven't looked into the first option (which we should eventually do), but the second option is easy to do with the following services:

• rosservice call /gazebo/get_world_properties "{}" to get a list of models in the world
• rosservice call /gazebo/get_model_state "model_name: '<model_name>' relative_entity_name: 'youbot'"to get the relative position of a model w.r.t the youbot. So we can get the objects which are "close" to the youbot and publish and object list with those.

[DharminB]

We need to use a better realsense camera plugin for perception in sim. Maybe as @sthoduka suggested https://github.com/pal-robotics/realsense_gazebo_plugin might be good.

[deebuls]

Pending things:

[ ] MoveIT needs to be fixed

• MoveIT doesnt say succceded