Initial version of new metainfo browser gui integration.

gui/src/components/MetaInfoRepository.js

gui/src/components/api.js

gui/src/components/metaInfoBrowser/DefinitionCard.js

gui/src/components/metaInfoBrowser/MetaInfoBrowser.js

gui/src/components/metaInfoBrowser/MetainfoSearch.js

gui/src/components/metaInfoBrowser/SectionFeature.js

gui/src/components/metaInfoBrowser/Viewer.js

gui/src/components/metaInfoBrowser/util/after-render.js

nomad/api/archive.py

tests/test_api.py