Hiding unused parameters behind VORB_UNUSED.

[MatthewJM96]

In order to get compilation to issue fewer warnings without disabling the warnings themselves, we have hidden all unused parameters behind a macro "VORB_UNUSED". This is a temporary measure and we want to review each location VORB_UNUSED is used, and follow the sequence:

1. Do we want to reimplement/revise the system in which the function resides?
   • If yes, do so or go to step 3.
2. Is the parameter unused in all compilation and logic paths of the code?
   • If yes, make the parameter anonymous;
   • If no, mark the parameter with VORB_MAYBE_UNUSED;
   • In either case remove the VORB_USED tag.
3. Find the next VORB_UNUSED-tagged parameter you want to tackle and go to step 1.