Add description parameter to plotTrajectory functions

[rjoomen]

• Add description parameter to plotTrajectory functions
• Add a plotTrajectories function to plot multiple trajectories in one set
• Minor API change: removed parameter ns from one function, as it was unused but might give the false impression it would be used instead of traj.ns
• Fixed the clear() function, as it removed all markers except the tool markers

[Levi-Armstrong]

Looks like there are a few clang-tidy errors

[rjoomen]

Looks like there are a few clang-tidy errors

That's right, Tesseract is full of clang-tidy errors with recent clang-tidy versions. They are not in the parts I changed here, though, I too care of that already. I'll start an effort correcting them throughout tesseract_ros2 soon, but for now I'll leave them, as it's a lot of work to correct them all.