Added ems domain to GUI. Fixed ems domain in backend.

dependencies/nomad-meta-info

dependencies/parsers/skeleton

gui/src/components/App.js

gui/src/components/Quantity.js

gui/src/components/dft/DFTEntryCards.js

gui/src/components/dft/DFTEntryOverview.js

gui/src/components/domains.js

gui/src/components/ems/EMSEntryCards.js

gui/src/components/ems/EMSEntryOverview.js

gui/src/components/ems/EMSSearchAggregations.js

gui/src/components/entry/Calc.js

gui/src/components/entry/RawFiles.js

gui/src/components/entry/RepoEntryView.js

gui/src/components/search/SearchPage.js

nomad-ems.yaml

nomad/datamodel/ems.py

nomad/processing/data.py

tests/processing/test_data.py

tests/test_api.py

tests/test_files.py