NPM: Add `jest`

[thibsy]

This PR adds jest as npm package.

Usage:

• components/ILIAS/UI/tests/Client/* (once unit-tests are migrated)

Wrapped By:

• Not applicable.

Reasoning:

• Uses syntax we are already familiar with, like describe() and it().
• mocha unit-tests can be easily migrated.
• We desperately need a JavaScript unit-testing framework.

Maintenance:

• The package is maintained actively, see GitHub releases.
• The package is widely used (11.5M on GitHub).

Links:

• Package manager: https://www.npmjs.com/package/jest
• GitHub: https://github.com/jestjs/jest
• Documentation: https://jestjs.io/docs/getting-started

[matthiaskunkel]

Jour Fixe, 22 JAN 2024: Dependency is accepted for ILIAS 10.

[klees]

This should have become part of ILIAS 10 via this PR. As always, something might have gone wrong. If you are still missing that package, please ping me.

Kind regards!