• feat: #2826 Lazy loading of widget content until visible (GridStackOptions.lazyLoad and GridStackWidget.lazyLoad)
• feat: #2818 support for Angular Component hosting true sub-grids (that size according to parent) without requring them to be only child of grid-item-content.
• fix: #2231,#1840,#2354 big overall to how we do sidepanel drag&drop helper. see migrate to v11 notes.
• fix: #2736 safe practices around GridStackWidget.content no longer setting innerHTML