Merge branch 'registrar-modularization' into 'staging'

.gitlab-ci.yml

README.md

client/html/View-Server_-_User-Guide_v1.1.1.pdf

client/html/prism.js

config/dem_init-db.sh

config/dem_registrar-config.yml

config/emg_init-db.sh

config/emg_registrar-config.yml

config/vhr18_init-db.sh

config/vhr18_registrar-config.yml

core/Dockerfile

core/registrar.py

core/registrar/__init__.py

core/registrar/backend.py

core/registrar/cli.py

core/registrar/config-schema.yaml

core/registrar/config.py

core/registrar/context.py

core/registrar/daemon.py

core/registrar/exceptions.py