pan/zoom and cursor refactor for better performance

bigbluebutton-html5/imports/ui/components/cursor/service.js

...n-html5/imports/ui/components/panel-manager/component.jsx

...on-html5/imports/ui/components/presentation/component.jsx

...on-html5/imports/ui/components/presentation/container.jsx

...5/imports/ui/components/presentation/cursor/component.jsx

...omponents/presentation/presentation-overlay/component.jsx

...omponents/presentation/presentation-overlay/container.jsx

...i/components/presentation/presentation-overlay/service.js

...omponents/presentation/presentation-toolbar/component.jsx

...omponents/presentation/presentation-toolbar/container.jsx

...i/components/presentation/presentation-toolbar/service.js

...utton-html5/imports/ui/components/presentation/service.js

...ui/components/whiteboard/whiteboard-overlay/component.jsx

...ui/components/whiteboard/whiteboard-overlay/container.jsx

...iteboard/whiteboard-overlay/cursor-listener/component.jsx

...d/whiteboard-overlay/pan-zoom-draw-listener/component.jsx

...ard/whiteboard-overlay/pencil-draw-listener/component.jsx

...ts/ui/components/whiteboard/whiteboard-overlay/service.js

...oard/whiteboard-overlay/shape-draw-listener/component.jsx

...board/whiteboard-overlay/text-draw-listener/component.jsx