Ground truth pose publishers should not publish static TFs

[peci1]

In all robot models, e.g.

subt/submitted_models/ctu_cras_norlab_absolem_sensor_config_1/launch/spawner.rb

Lines 107 to 109 in 9b8c41f

	<publish_nested_model_pose>#{$enableGroundTruth}</publish_nested_model_pose>
	<use_pose_vector_msg>true</use_pose_vector_msg>
	<static_publisher>true</static_publisher>

the ground truth pose is published as a static TF. It works, but it's not right, because static TFs should only be used for transforms that do not change or change only occasionally.

I think it could be fixed by adding this snippet to all robots:

    <plugin filename="libignition-gazebo-pose-publisher-system.so"
        name="ignition::gazebo::systems::PosePublisher">
        <publish_link_pose>false</publish_link_pose>
        <publish_sensor_pose>false</publish_sensor_pose>
        <publish_collision_pose>false</publish_collision_pose>
        <publish_visual_pose>false</publish_visual_pose>
        <publish_nested_model_pose>#{$enableGroundTruth}</publish_nested_model_pose>
        <use_pose_vector_msg>true</use_pose_vector_msg>
        <static_publisher>false</static_publisher>
      </plugin>

and setting

    <publish_nested_model_pose>false</publish_nested_model_pose>

in the static transform snippets.

[acschang]

Related to #659

[peci1]

Solution proposed in #759.

[iche033]

the changes look good to me and would resolve the issue that model poses are incorrectly published to the pose_static topic.

This makes me think that the PosePublisher system should really just be classifying a model / nested model entity as a dynamic entity instead of a static one (in which case, we would just insert the entity into the dynamic entities list somewhere around here, i.e. if (nestedModel) this->dynamicEntities.insert(entity))