During Audit, Comment field is not cleared after adding a new Comment

### Current Behavior

I've set up a Policy Violation rule. When something came up, I open up the violation and add a Comment to follow what will be done :

After adding the Comment, it appears in the Audit Trail. But the text stays in the Comment Box. Depending on the text already present in the Audit Trail, the user could think that their comment was not send, and click again to send it.

### Proposed Behavior

It would be better if the "Comment field" was cleared after sending the comment

### Checklist

- [x] I have read and understand the [contributing guidelines](https://github.com/DependencyTrack/dependency-track/blob/master/CONTRIBUTING.md#filing-issues)
- [x] I have checked the [existing issues](https://github.com/DependencyTrack/frontend/issues) for whether this enhancement was already requested