Feat: Add NodeResizer package

[moklick]

This PR add a @reactflow/node-resizer package that exports two components that can be used inside a custom node as a helper to resize a node:

1. <NodeResizer />

This component adds four handles (top-left, top-right, bottom-right and bottom-left) and four lines (top, right, bottom, left) to resize a node.

Props:

type NodeResizerProps = {
  nodeId: string;
  handleClassName?: string;
  handleStyle?: CSSProperties;
  lineClassName?: string;
  lineStyle?: CSSProperties;
};

2. <NodeResizeControl />

This component can be used for creating a custom resize UI.

Props:

type ResizeControlProps = {
  nodeId: string;
  position: ControlPosition;
  variant?: ResizeControlVariant;
  className?: string;
  style?: CSSProperties;
  children?: ReactNode;
};