Get available query options for node groups

Returns available filters and sorting options for querying node groups. Filter options may be simple strings (e.g., health statuses, GPU types) or hierarchical objects (e.g., compute zones with nested nodegroups). Filter options examples: - Simple strings: `{"name": "healthStatuses", "options": ["Healthy", "Degraded", "Unhealthy"]}` - Hierarchical objects: `{"name": "computeZones", "options": [{"id": "cz-1", "value": "Zone 1", "options": [{"id": "ng-1", "value": "Node Group 1"}]}]}`