Moved polyfills & improved deep link handling

[ignaciosantise]

Summary

• Applying polyfills in the main file of the SDK to simplify installation process for devs
• Setting localstorage key with wallet data after the session is created
  • Added a config value to save the data temporarily
• Added ethers as a dependency of the example app

[github-actions[bot]]

🚀 Expo preview is ready!

• Project → web3modal-rn-example
• Platforms → android, ios
• Runtime Version → exposdk:48.0.0
• More info

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