Edit license

### Current Behavior

Licenses can only be added or deleted

### Proposed Behavior

One should be able to edit the license (e.g. 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/dependency-track/issues) for whether this enhancement was already requested

Start by tracing the existing license add and delete flow in the project and identify where license comments are stored and exposed. Confirm the expected edit behavior with the issue context, then verify that a license comment can be changed while existing add and delete behavior remains intact.

Written by the indexing model from the issue text.