Create ESM bundle for ESM related projects (Astro, Svelte, Vite, and newer version of Next.js)

[xiaolin]

Describe the bug
The current webpack bundle only builds UMD which is causing issues with projects in ESM environment.

Image Gallery Version
What version of react-image-gallery are you using?

To Reproduce
Steps to reproduce the behavior:

1. Create a project using Astro
2. Import this library
3. It breaks

Expected behavior
It should work with ESM projects

[xiaolin]

Current workaround for ESM projects is to do the below.

import Gallery from 'react-image-gallery';
const ImageGallery = Gallery.default ? Gallery.default : Gallery;