F/patterndb lookup refactor

This series refactors the montruous r_find_node() function in radix-find.c into smaller chunks.

I've left the refactor steps intact, sometimes the same thing is renamed multiple times, however I've felt it is easier to review/validate the individual steps than the entire series.

If you need, you can review the entire before/after changes just looking at the last patch, that simply gets rid off radix-find.c and pastes its entire content into the radix.c file.

Please merge.