Feat(nodes): add initialWidth and initialHeight (#3953)

* feat(react/svelte): add initialWidth/initialHeight closes #3793

* chore(packages): update changelogs

examples/astro-xyflow/src/components/ReactFlowInitialExample/CustomNode.tsx

@@ -0,0 +1,21 @@
+import { memo, useState } from 'react';
+import { Handle, Position } from '@xyflow/react';
+
+function CustomNode() {
+  const [text, setText] = useState('this is a pretty long text');
+
+  return (
+    <>
+      <Handle type="target" position={Position.Top} />
+      <div style={{ background: '#eee', padding: 10 }}>
+        <div>
+          <input value={text} onChange={(e) => setText(e.target.value)} />
+          <div>text: {text}</div>
+        </div>
+      </div>
+      <Handle type="source" position={Position.Bottom} />
+    </>
+  );
+}
+
+export default memo(CustomNode);