Use when controlling Pexip meeting layouts — host layout vs personal layout, layout overlay text, lecture-mode guest layout, presentation-in-mix detection, fetching available layouts and their SVGs from the server. Triggers on `meeting.changeLayout`, `meeting.changePersonalLayout`, `setLayout`, `setPersonalLayout`, `availableLayouts`, `layoutSvgs`, `currentHostLayout`, `pres_slot_coords`, `transform_layout`, `enable_overlay_text`, `lecture` service type.
