Refactor room overview components

Create modules for room overview page for both participant and editor and create standalone components for room overview header and room overview action buttons. Use lazy loading for RoomOverviewModules.

Furthermore make independent components as CopyUrlComponent, DividerComponent, ContentGroupsComponent and RenderedTextComponent standalone too.

Create common folder which contains abstract classes and styles.

Note: Apart from the fact that the room link can now also be copied in the room overview of the participants, nothing should have changed in terms of behaviour and appearance.

Closes #1080 (closed)