Function parse_attribute_condition 

pub fn parse_attribute_condition(
    label: &str,
    data_type: AttributeType,
    raw: &str,
) -> Result<AttributeCondition, AppError>

Parses a search value for an attribute of data_type: empty = has a value; text and choices match as substring; yes/no; numbers accept 12, >=10, <=20 and 10..20 (no 10-20, which would clash with negative numbers).