test: add e2e tests for datafiles action

[Junjiequan]

Description

1. Added e2e test for datafiles actions (download/notebook for selected/all).
2. Refactored to use a single file for test data (testData.js).
3. Removed old fixture files (derivedDataset, rawDataset, etc.).
4. Updated ESLint configuration and added parser options.
5. Added new datafiles actions in config files.
6. Adjusted Cypress commands to use the new test data structure.
7. Removed unnecessary access token passing in API calls.

Motivation

Background on use case, changes needed

Fixes:

Please provide a list of the fixes implemented in this PR

• Items added

Changes:

Please provide a list of the changes implemented by this PR

• changes made

Tests included

• [ ] Included for each change/fix?
• [ ] Passing? (Merge will not be approved unless this is checked)

Documentation

• [ ] swagger documentation updated [required]
• [ ] official documentation updated [nice-to-have]

official documentation info

If you have updated the official documentation, please provide PR # and URL of the pages where the updates are included

Backend version

• [ ] Does it require a specific version of the backend
• which version of the backend is required:

[sonarqubecloud[bot]]

Quality Gate failed

Failed conditions
14.0% Duplication on New Code (required ≤ 3%)

See analysis details on SonarCloud