Added CVSS Environmental metrics

[Iorpim]

Issue

#232

Description of the Change

This PR adds support for CVSS 3.0 Environmental metrics to the CVSS calculator.
The bulk of the changes are purely the addition of a new form and part of the JavaScript to handle it, with the exception of the change to the Finding model, increasing the length of the cvss_vector field to fit the new increased vector with additional metrics.
The Environmental calculator was added only when editing a finding inside a report as it's supposed to be a more case-by-case metric and not intrinsic to the vulnerability.
Temporal metrics were also omitted due to their smaller relevance for pentest reporting. However, implementation is trivial if required.
One possible future improvement is adding a new field in the Finding model, storing the Base and Environmental scores separately so they can both be laid out in reports.

Alternate Designs

N/A

Possible Drawbacks

The only downside is making the calculator a little more full, another reason the less relevant Temporal metrics were excluded in this change. The calculator can be easily collapsed, however.

Verification Process

The changes are almost purely front-end and very granular so changes were manually tested, scores were compared to the NIST calculator, and new findings were created and edited with and without environmental metrics.

Release Notes

• Added CVSS 3.0 Environmental metrics to the CVSS calculator

[Iorpim]

One additional note is that the previous linting configurations are deprecated in newer versions of VS Code, so the external dependencies were migrated to the official recommended extensions instead, and added to the extensions.json file for easier setup.

A side effect is that longer lines were automatically split up into multiple line statements by the linter. If this is undesired, changes can be cherrypicked without affecting the PR functionality, however, deprecation of external linters should be noted in that case.

[chrismaddalena]

Thanks for submitting this! I will take a look at it soon. I will try to look at it before I leave on a trip, but it may be toward the end of the month if not.