ENH: add file-upload.js

Summary

1. Add legacy adapter for the new FileUpload widget and integrate it into the legacy web interface (file system view).
2. fix some minor issues with links to the file system

related: caosdb/customers/geomar/management#129

Focus

The new code is mainly concerned with integrating the file upload into the file system view. However, it is very easy to use the widget separately for a custom form (see geomar code for example).

Test Environment

Test with geomar setup

Check List for the Author

• All automated tests pass
• Reference related issues
• Up-to-date CHANGELOG.md (or not necessary)
• Up-to-date JSON schema (or not necessary)
• Appropriate user and developer documentation (or not necessary)
  • How do I use the software? Assume "stupid" users.
  • How do I develop or debug the software? Assume novice developers.
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md (or not necessary)
• Appropriate user and developer documentation (or not necessary)
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there specifications? Are they satisfied?

For further good practices have a look at our review guidelines.