New API endpoints for AI metrics

Added

Dashboards APIs: - GET /v2/metrics/ai/usage/details - GET /v2/accounts/{accountId}/metrics/ai/usage/details - GET /v2/metrics/ai/adoption - GET /v2/accounts/{accountId}/metrics/ai/adoption - GET /v2/metrics/ai/kpis - GET /v2/accounts/{accountId}/metrics/ai/kpis - GET /v2/metrics/ai/usage/trend - GET /v2/accounts/{accountId}/metrics/ai/usage/trend