feat: migrate to ESM and vitest

[npalm]

Description

This PR migrates the TypeScript testing framework from Jest to Vitest and transitions the codebase from CommonJS (CJS) to ECMAScript Modules (ESM).

Motivation:

• Moving from Jest to Vitest:
  • Performance: Vitest leverages Vite's build pipeline, resulting in significantly faster test execution, especially in larger projects. This speed improvement enhances developer productivity by providing quicker feedback loops.
  • Vite Integration: For projects already using Vite, Vitest offers seamless integration, reducing configuration overhead and providing a unified development experience.
  • Modern tooling: Vitest is a modern test framework that is actively being developed and provides a better developer experience.
• Migrating from CJS to ESM:
  • Modern JavaScript: ESM is the official standard for module systems in modern JavaScript, offering better static analysis, tree-shaking, and overall performance.
  • Improved Compatibility: ESM is the future of JavaScript modules and ensures better compatibility with modern tooling and libraries.
  • Simplified Dependency Management: ESM's static imports allow for more efficient dependency management and better optimization by bundlers.

Changes:

• Replaced Jest with Vitest for unit testing.
• Updated test files to adhere to Vitest syntax.
• Updated configuration files to reflect the changes (e.g., package.json, tsconfig.json).

Testing:

• The changes should not introduce any functional regressions. Thoroughly verify existing test suites using Vitest.
• It is advisable to clear any local cache, such as node_modules and dist folders, before building the lambda functions yourself.
• Chages are tested with
  • Default example
  • Multi runner example

Related Issues:

• Fixes ESM support #3964
• Fixes [refactor] - migrate lambdas to vitest form jest #4366

Potential Risks:

• While the migration aims for seamless transition, there's a possibility of encountering minor compatibility issues during the initial build or test runs. Thorough testing and cache clearing should mitigate these risks.

Additional Notes:

• This migration modernizes the project's tooling and module system, laying a foundation for future improvements and maintainability.

[npalm]

@rjaegers what would you say. The change should not be breaking, but it is a big one. I am consider to mark it as a breaking to make the end user aware of this change. Although tested the risk is bigger than most osther changes. What is your view?

[npalm]

@rjaegers updated, removed useless comments.