robot footprint model access specifiers loosened

[rayvburn]

I propose minor changes in robot_footprint_model to allow more extension possibilities (for e.g. planners which use similar environment representation).

• BaseRobotFootprint class
  • getInscribedRadius was a non-const method even though none of the members are changed in any of derived classes
• TwoCirclesRobotFootprint class
  • front_offset, front_radius, rear_offset, rear_radius are marked as private which kinda blocks extension possibilities
• LineRobotFootprint class
  • transformToWorld method was private, similarly, line_start and line_end

[amakarow]

Thank you, looks good, but kinetic is outdated. Do you really need this in kinetic? We would prefer to merge into melodic/noetic.

[rayvburn]

Sure that Kinetic is pretty old but e.g. PAL's software for TiAGo robot seems to work best with that distro. Having that in Kinetic would be very helpful!