fix missing select icon

[haroun]

Summary

Add missing form select widget icon

What are the specific steps to test this change?

⚠️ the icons are displayed only in the editor modal

1. Open the widget editor modal
2. When you click on the Add Content button you must see an icon for the select widget

If you see the following it's a failure

What kind of change does this PR introduce?

(Check at least one)

• Bug fix
• New feature
• Refactor
• Documentation
• Build-related changes
• Other

Make sure the PR fulfills these requirements:

• It includes a) the existing issue ID being resolved, b) a convincing reason for adding this feature, or c) a clear description of the bug it resolves
• The changelog is updated
• Related documentation has been updated
• Related tests have been updated

If adding a new feature without an already open issue, it's best to open a feature request issue first and wait for approval before working on it.

Other information: