react-lottie is abandoned and uses deprecated lifecycle methods

[zwliew]

Describe the bug
react-lottie is the library we use to render the landing page animation. It appears to be abandoned and uses deprecated lifecycle methods (componentWillUpdate).

This is an issue because the lifecycle method will be removed in future React versions.

To Reproduce
Steps to reproduce the behavior:

1. Run the frontend in development mode locally
2. There should be a console warning (see: Move data fetching code or side effects to componentDidUpdate. chenqingspring/react-lottie#119 (comment))

Expected behavior
There should be no console warning.

Possible Solution
We can migrate to the lottie-react library. It fixes the issue and is expected to have React 17 support soon. Furthermore, the library is written in TypeScript and seems to have better code quality compared to other alternatives like react-lottie-player.

[zwliew]

Fix merged