Merge branch 'dbp-translation-component' into 'master'

packages/common/i18next.js

packages/common/src/i18n.js

packages/common/src/translation.js

packages/theme-switcher/src/demo.js

packages/theme-switcher/src/i18n.js

packages/theme-switcher/src/i18n/en/translation.json

packages/theme-switcher/src/theme-switcher.js

toolkit-showcase/assets/theme-switcher.metadata.json

...showcase/assets/translation-overrides/de/translation.json

...showcase/assets/translation-overrides/en/translation.json

toolkit-showcase/src/dbp-theme-switcher-demo-activity.js