Update editor for new slide out context menu
Update panel page layout editor
Unify row and column handler

We refactor the panel grid view to provide a single management
location for grid blocks and panels
Update delete action
Prepare rendered panelgrid
Update block editor to include rendered panel grid
Use content menus throughout the toolchain
Refacttor panel grid ratio selection
Prepare rewrite of panel managment
Introduce image panel content type
Add listing panel
Add listing panel tempaltes
Enhance panel management