Allow project scoped CVSS analysis override

### Current Behavior

Currently, Dependency-Track only knows the Severity and CVSS scores of a vulnerability as provided for the component.
However, during triage you should decide how critical the vulnerability is for the current project which includes the projects specific risk factors for exploitation. For some projects this might be the same as the Severity of the component, while for others this may be different. E.g. if a component is only used in an area used by high-privileged users.
Depending on this analysis you might need different prioritization.

### Proposed Behavior

In the vulnerability audit you should have an option to provide a custom CVSS vector (ideally with UI calculator support) which applies to the scope of this single project. Opening it should default to the values from the vulnerability (if available), but with the possibility to adjust it.
This value should then be used in the projects context for notifications, UI etc. wherever severities and CVSS scores are displayed. Ideally an indicator in the UI and API can show if a custom value is set, which deviates from the value provided from the original vulnerability.

### 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