Feeedback length error checking

[amin-xiv]

Description

Added error checking for the message field on the feedback form.

Related Issue

Fixes #337

Type of change

• Bug fix
• New feature

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented on my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[github-actions]

🎉 Thank you for your contribution! Your pull request has been submitted successfully. A maintainer from team will review it as soon as possible. We appreciate your support in making Dataverse better.

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[github-actions]

🎉🎉 Thank you for your contribution! Your PR #339 has been merged! 🎉🎉