refactor(utils): add getElementsToRemove and use in react and svelte packages

packages/svelte/src/routes/+page.svelte

@@ -128,6 +128,7 @@
   minZoom={0.1}
   maxZoom={2.5}
   initialViewport={{ x: 100, y: 100, zoom: 2 }}
+  defaultEdgeOptions={{ animated: true }}
   on:node:click={(event) => console.log('on node click', event)}
   on:node:mouseenter={(event) => console.log('on node enter', event)} 
   on:node:mouseleave={(event) => console.log('on node leave', event)}
@@ -136,7 +137,7 @@
   on:connect={(event) => console.log('on connect', event)}
   on:connect:end={(event) => console.log('on connect end', event)}
   on:pane:click={(event) => console.log('on pane click', event)}
-  on:pane:contextmenu={(event) => { console.log('on pane contextmenu', event); }}
+  on:pane:contextmenu={(event) => { event.preventDefault(); console.log('on pane contextmenu', event); }}
 >
   <Controls />
   <Background variant={BackgroundVariant.Dots} />