Add test suite using Vitest

[lucas-varela]

Description

Like the JS SDK, we need to implement tests to validate our components. However, unlike the JS SDK, the React SDK doesn't make any requests, but exports React components instead.

With this in mind, we need to implement snapshot tests to verify if our components render correctly.

Requirements

• Create a new branch off main called feature/tests.
  • The DynamicForm component branch won't be merged until we finish this task. This means that you won't write tests for the form component in this task.
• Install and configure Vitest.
  • Read the docs on how to install Vitest on a new project.
  • Feel free to copy JS SDK's configuration file (vitest.config.js).
  • The React SDK doesn't make any requests, which means that we don't need to install MSW.
• Implement test cases for both React components exported by the SDK:
  • VisualContent
  • ResponsiveImage

Additional info

• Vitest documentation on snapshots: https://vitest.dev/guide/snapshot.html
• Tutorial on how to configure Vitest with React and how to test React components: https://mayashavin.com/articles/test-react-components-with-vitest