Add read endpoint for court blocks

createcourtblock/updatecourtblock/deletecourtblock exist in the v1 API but there's no corresponding list/get endpoint. Without it, third-party reporting integrations can't reproduce the Court Utilization Report — operator-placed blocks count toward CR's calculation but are invisible to API consumers. Request: GET /api/v1/reservation/courtblocks?startDate=...&endDate=.... Use case: reconciling utilization metrics for executive dashboards / multi-system reporting layers.