Add Task's setRobotModel to python binding

[JafarAbdi]

I was testing this with moveit2's python binding and got the following error subsolutions refer to multiple robot models when using a planning scene from MoveItPy.

[rhaschke]

Can you please provide the code causing issues with this? Probably, different RobotModel instances are in use...

[JafarAbdi]

Here is the code-snippet

task = core.Task()
# This fails
# task.loadRobotModel(node)
# This works
task.setRobotModel(planning_scene.robot_model)

task.name = "pick + place"

pipeline = core.PipelinePlanner(node, "ompl", "RRTConnectkConfig")
planners = [(arm, pipeline), (eef, pipeline)]

fixed_state = stages.FixedState("current")
fixed_state.setState(planning_scene)
task.add(fixed_state)

# Connect the two stages
task.add(stages.Connect("connect", planners))

Note that I'm using a planning scene constructed with MoveItPy, I think it's because we only check for the memory location in merge.cpp