Fix bio validation value comparisons

[marfox]

• [x] avoid incorrect comparisons of string values, e.g., Q1511,P20,venice,eefd7c1e-abcf-4ccc-ba60-0fd435c9061f should not be in the extra set;
• [x] investigate empty string values, e.g., Q3036,P20,,7779ce76-342b-43ed-a4e9-76145e1f57ef;
• [x] keep track of QID values for places and gender, e.g., Q1511,P20,venice,eefd7c1e-abcf-4ccc-ba60-0fd435c9061f --> Q1511,P20,Q641,eefd7c1e-abcf-4ccc-ba60-0fd435c9061f.