security/vuxml: document grafana{8,9} CVEs

• CVE-2023-0507 - Stored XSS in geomap panel plugin via attribution (High)
• CVE-2023-0594 - Stored XSS in TraceView panel (High)
• CVE-2023-22462 - Stored XSS in text panel plugin

PR: 269903
Reported by: drtr0jan@yandex.ru