Dynamic parameter changes with `rqt_reconfigure`

[juliangaal]

This PR adds full support for the dynamic configuration of runtime parameters with rqt_reconfigure while maintaining compatibility with setting params in params.yaml.

The changed are quite large, so don't hesitate to ask me questions about changes.

If you consider merging, two things to note:

• I am pretty sure parameter "mode" is unused. I think it can be removed
• Please help me by setting sane min/max values in Patchworkpp.cfg and add additional configuration checks for validity in patchworkpp/params.h
• I did take the liberty to remove unused variables and fix some sign issues (int/size_t)

Let me know if you are interested in this PR.