feat(tocco-util): add legacy-widget embedType
feat(tocco-util): add legacy-widget embedType

- being able to distinguish between widget and legacy-widget
- legacy-widget: entity-browser and docs-browser
  which are used in legacy CMS
- do not apply new widget theme to legacy-widget
- hide detail meta information for legacy-widget too

Refs: TOCDEV-4571
Cherry-pick: Up
Changelog: add legacy-widget embedType

tocco/tocco-client,tocco/tocco-client,tocco/tocco-client