Add back yaml-cpp/yaml.h header file for convert<> class template.
Reorder member variables in initialize list to fix gcc build warnings.
Merge branch 'fix/serialize-builderror' into 'master'

Fix Jenkins build error caused by missing yaml.h in Convert.h.

+1: haizhouW, kelliher

Merged-on: https://www.assembla.com/code/OpenSurgSim/git/merge_requests/796913