consider adding `SlowMovementCostFunction`

[rayvburn]

The aim of this cost function is to keep linear speed close to the maximum allowable (defined by the kinematic constraint)

[rayvburn]

Added to the non-main branch, see https://github.com/rayvburn/hubero_local_planner/tree/planning/feature-slow-translation-costfun

[rayvburn]

• [X] Also, slow_translation_costs_(), can be deleted from init list of the planner class.

 STR %6.1f "
// ...
slow_translation_costs_.getScale() * slow_translation_costs_.scoreTrajectory(traj_copy),

[rayvburn]

This will not be merged

[rayvburn]

It may be useful in some situations. Consider renaming that to UnsaturatedTranslationCostFunction

[rayvburn]

Imported to the main devel branch with a default scale set to 0.0. The scale might be later changed in https://github.com/rayvburn/hubero_local_planner/issues/92