get rid of the `ContextualizedCostFunction`

[rayvburn]

the classical ObstacleCostFunction does the same plus checks if footprint is in a legal position (collision-free)

[rayvburn]

Examined if ObstacleCostFunction operates using the resultant costmap that has all layers embedded and it is true.

What was compared:

• direct cost calculation of a costmap

  occ_cost = planner_util_->getCostmap()->getCost(cx, cy);

• footprint cost calculation with the ObstacleCostFunction

  obs_cost = obstacle_costs_.footprintCost(cx, cy, 0, costmap_2d::makeFootprintFromRadius(1e-06));

A new channel was added to the PCL created with createCostGridPcl method - obs_cost. With a circular footprint created with 1e-06 radius, the obs_cost channel duplicates occ_cost. By this means, the ObstacleCostFunction cost function uses the resultant costmap (with obstacles and social contexts, if enabled), so there is no need to use ContextualizedCostFunction