feat: add GroundValueChecker and WeatherSensorDevice with public API integration

This commit introduces two new device types, GroundValueChecker and WeatherSensorDevice, which leverage public APIs (BORIS NRW and Open-Meteo) for real-time data collection. It also includes several API enhancements and fixes to support these new integrations.

Detailed changes:
- **New Device Types**:
  - Added GroundValueChecker schema and integration with BORIS NRW WMS via Zabbix Script items.
  - Added WeatherSensorDevice schema and integration with Open-Meteo via Zabbix HTTP Agent items.
- **API Enhancements**:
  - Added error field to ZabbixItem for item-level error reporting.
  - Updated CreateTemplateItem mutation input to support params (for Script items) and timeout.
  - Registered missing scalar resolvers: JSONObject, DateTime, and Time.
- **Performance & Reliability**:
  - Implemented batch fetching for item preprocessing in both host and template queries to reduce Zabbix API calls and ensure data visibility.
  - Updated template_importer.ts to correctly handle Script item parameters.
- **Documentation**:
  - Consolidated public API device recipes in docs/howtos/cookbook.md.
  - Added guidance on analyzing data update frequency and setting reasonable update intervals (e.g., 1h for weather, 1d for ground values).
- **Testing**:
  - Added new regression test REG-ITEM-META to verify item metadata (units, description, error, preprocessing) and JSONObject scalar support.
  - Enhanced RegressionTestExecutor with more detailed host-item relationship verification.

docs/queries/sample_import_weather_sensor_template.graphql

@@ -39,7 +39,7 @@ The following variables define the `WEATHER_SENSOR` template. It uses the host's
           "key": "weather.get",
           "value_type": 4,
           "history": "0",
-          "delay": "1m",
+          "delay": "1h",
           "url": "https://api.open-meteo.com/v1/forecast?latitude={$LAT}&longitude={$LON}&current=temperature_2m,weather_code",
           "description": "Master item fetching weather data from Open-Meteo based on host coordinates."
         },
@@ -49,6 +49,8 @@ The following variables define the `WEATHER_SENSOR` template. It uses the host's
           "key": "state.current.temperature",
           "value_type": 0,
           "history": "7d",
+          "units": "°C",
+          "description": "The current temperature at the device location.",
           "master_item": {
             "key": "weather.get"
           },
@@ -65,6 +67,7 @@ The following variables define the `WEATHER_SENSOR` template. It uses the host's
           "key": "state.current.streetConditionWarnings",
           "value_type": 4,
           "history": "7d",
+          "description": "Human-readable weather warnings or descriptions derived from weather codes.",
           "master_item": {
             "key": "weather.get"
           },