OZG-6302 OZG-6408 impl buttons and view switch

...ollaboration-shared/src/lib/collaboration.service.spec.ts

...ibs/collaboration-shared/src/lib/collaboration.service.ts

...ntainer/collaboration-in-vorgang-container.component.html

...ntainer/collaboration-in-vorgang-container.component.scss

...iner/collaboration-in-vorgang-container.component.spec.ts

...container/collaboration-in-vorgang-container.component.ts

...lle-container/zustaendige-stelle-container.component.html

...-container/zustaendige-stelle-container.component.spec.ts

...telle-container/zustaendige-stelle-container.component.ts

...client/libs/collaboration/src/lib/collaboration.module.ts

alfa-client/tsconfig.base.json