fix(): default value when add item in array widget

[jmainguytalend]

What is the problem this PR is trying to solve?

What is the chosen solution to this problem?

Please check if the PR fulfills these requirements

• [ ] The PR have used yarn changeset to a request a release from the CI if wanted.
• [ ] The PR commit message follows our guidelines
• [ ] Tests for the changes have been added (for bug fixes / features) And non reg done before need review
• [ ] Docs have been added / updated (for bug fixes / features)
• [ ] Related design / discussions / pages (not in jira), if any, are all linked or available in the PR

[ ] This PR introduces a breaking change