feat: Allow specifying unit per Apdex
Dashboard snapshot for fixed ai-gateway latency: https://dashboards.gitlab.net/dashboard/snapshot/BMAYB0l2GsowS8BiXGwmHiVo79CIXPCZ?orgId=1&viewPanel=40
Dashboard snapshot for fixed ai-gateway latency: https://dashboards.gitlab.net/dashboard/snapshot/BMAYB0l2GsowS8BiXGwmHiVo79CIXPCZ?orgId=1&viewPanel=40