Level up perfomance of LiDAR storage & processing

[dorkamotorka]

This PR improves LiDAR data storage in two ways:

• std::vector function reserve() is used, which allocates enough memory in the Free-Store so there is no need for resizing and copying all of the data of the std::vector to the new memory location when this happens
• Lookup Tables for Sine and Cosine of theta(LiDAR angle) are used, because std::sin() and std::cos() are quite costly operation that where repeatedly used in our callbacks.

I did profile the code myself on my PC and experienced 30-50% less time consumed on these for loops. To give you a sense in seconds - Firstly the for loop took ~140 microseconds, afterwards it took ~60 microseconds.

[JanezCim]

do you need only code review or do i need to test on Gazebo and/or real robot?

[dorkamotorka]

Please test both.

[dorkamotorka]

I created a Lidar class which can be useful in future if we would modify this node to be able to accept point from multiple lidar sources. Please re-test.

Object is created because we need to access lidar meta data from the callback and a method get_points and not only from the callback.