Support proper CVSS v4 severity mapping for SonarQube standard mode

[mai-67]

Describe the bug
Currently, the plugin does not correctly map vulnerability severity when SonarQube is configured in standard mode.

To Reproduce

Current behavior
The plugin relies on LOW/MEDIUM/HIGH severity levels, while SonarQube uses BLOCKER/CRITICAL/MAJOR/MINOR.

Additionally, CVSS v4 scores are not properly considered, leading to incorrect severity classification (e.g., CVSS v4 Critical vulnerabilities being reported as MEDIUM).

Expected behavior
The plugin should:

1. Support CVSS v4 scoring
2. Map severity according to SonarQube standard model:

CVSS v4 ≥ 9.0 → BLOCKER
CVSS v4 ≥ 7.0 → CRITICAL
CVSS v4 ≥ 4.0 → MAJOR
CVSS v4 < 4.0 → MINOR

3. Optionally adapt behavior depending on SonarQube mode (Standard vs MQR)

Screenshots

Versions (please complete the following information):

• dependency-check 12.2.0
• sonarqube comunity 26.0
• dependency-check-sonar-plugin 6.0