Routes for group specific vocab activation

[noctera]

In order to implement the group specific activation in the frontend we need some routes in the backend.

1. Update Route
   /api/languagePackage/:languagePackageId/group
   Add query Parameter ?staged=true to only return groups that contain unactivated/staged vocabs

2. Update Route
   /api/group/:groupId/vocabulary
   Add query Parameter ?staged=true to only return vocabs that are unactivated

3. Update Route
   /languagePackage/:languagePackageId/query
   Add query Parameter ?groupId={groupId}&groupId={groupId} to return only vocabs from these group
   (the staged parameter is already implemented. If groupIds are given this route should give back vocabs independently of the current status/stage. This gives the ability to add custom learning in the future vocascan/vocascan-frontend#126)