refractor: cleanup & combine core dryvr pieces

dryvr_plus_plus/scene_verifier/dryvr.py

dryvr_plus_plus/scene_verifier/dryvr/__init__.py

dryvr_plus_plus/scene_verifier/dryvr/common/__init__.py

dryvr_plus_plus/scene_verifier/dryvr/common/config.py

dryvr_plus_plus/scene_verifier/dryvr/common/constant.py

dryvr_plus_plus/scene_verifier/dryvr/common/io.py

dryvr_plus_plus/scene_verifier/dryvr/common/utils.py

dryvr_plus_plus/scene_verifier/dryvr/core/__init__.py

dryvr_plus_plus/scene_verifier/dryvr/core/distance.py

dryvr_plus_plus/scene_verifier/dryvr/core/dryvrcore.py

dryvr_plus_plus/scene_verifier/dryvr/core/dryvrmain.py

dryvr_plus_plus/scene_verifier/dryvr/core/goalchecker.py

dryvr_plus_plus/scene_verifier/dryvr/core/graph.py

dryvr_plus_plus/scene_verifier/dryvr/core/guard.py

dryvr_plus_plus/scene_verifier/dryvr/core/initialset.py

dryvr_plus_plus/scene_verifier/dryvr/core/initialsetstack.py

dryvr_plus_plus/scene_verifier/dryvr/core/reachtube.py

dryvr_plus_plus/scene_verifier/dryvr/core/reset.py

dryvr_plus_plus/scene_verifier/dryvr/core/uniformchecker.py

...s_plus/scene_verifier/dryvr/discrepancy/PW_Discrepancy.py