Field suggestions in form playground input lead to validation error

[barmac]

Describe the bug

In the form playground input, I can provide a JSON for the variables. The editor suggests the form fields keys, but as soon as they are added, the JSON is invalid. This leads to bad UX.

Steps to reproduce

1. Add a form field
2. Start typing in JSON input.
3. now this happens

Expected behavior

No suggestions beyond valid JSON values (e.g. null, true, false).

Environment

• OS: [e.g. MacOS 10.2, Windows 10]
• Camunda Modeler Version: 5.29.0, 5.30.0, maybe even earlier.
• Execution Platform: [e.g. Camunda 7, Camunda 8]
• Installed plug-ins: [...]

Additional context

No response