Extend footprint_filter for non circular robots

[jcarlosgm30]

Hi!

The current implementation of footprint_filter is only for circular robots. It would be very useful if we extend the filter to be used by non-circular robots including a footprint in a similar format as NAV2.

what do you think about this? @jonbinney

[jonbinney]

Yes, definitely useful! I think the polygon filter does that in ROS1, and there is actually a PR by @berend-kupers to port it (and other filters) to ROS2: https://github.com/ros-perception/laser_filters/pull/189/files . Its a big PR and I haven't had time to review it - if you have some time and can do a review that would help move it along!