Request moving package workspace_visualization header files into a include/workspace_visualization directory

[Levi-Armstrong]

[jontromanab]

@Levi-Armstrong Actually some packages that uses plugin in Rviz has also put the include files in the /src instead of /include/ including rviz plugin tutorial

If you still want to move it to /include folder, this will take no effort. Please let me know and I will move them instantly