Add zero-time cloud2base transformation

[nachovizzo]

          This we have to modify to correctly handle a non-static `cloud2base` transformation.

Since kiss_pose is expressed w.r.t the first frame of the sensor at time 0, cloud2base transforms between sensor and base link in at the current timestep (which is in case of a non-static tf not necessarily the same as the one at time 0).

Should be something like

return cloud2base_ref.inverse() * kiss_pose * cloud2base_current;

Originally posted by @benemer in #232 (comment)

Also mentions #232 (comment)

Fix

• Fix transformation Add support for multi-sensor scenarios #232 (comment)
• Fix map transformation Add support for multi-sensor scenarios #232 (comment)