Get available query options for nodes

Returns available filters and sorting options for querying nodes. Filter options may be simple strings (e.g., health statuses) 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"}]}]}`