Add new jsonb type column to message table , with some additional values

[david-i-berry]

• For extensibility add JSONB column for storing additional fields.
• Add field to config to specify the additional columns.

[david-i-berry]

Add pressure reduced to sea level as example field for testing.

[celgarrai]

done

[maaikelimper]

@celgarrai don't store required_fields in jsonb : https://github.com/wmo-im/wis2-data-analysis/blob/0fd8b03b982de43dd508d83e25fc8ed098d063da/database_manager.py#L41C14-L64

@maaikelimper to provide eccodes-keys for other variables (check with Timo)

[maaikelimper]

Timo suggests these columns: 'observed_property_pressure_reduced_to_mean_sea_level', 'observed_property_air_temperature', 'observed_property_dewpoint_temperature', 'observed_property_relative_humidity', 'observed_property_wind_direction', 'observed_property_wind_speed', 'observed_property_non_coordinate_pressure'

There first one we already have so remaining variables: airTemperature dewpointTemperature relativeHumidity windDirection windSpeed nonCoordinatePressure