Validate request

...

1. if tax_id is not null and age>=16
   1. search fields: tax_id, first_name, last_name, birth_date
   2. additional fields: second_name,  birth_certificate, phonephone_number
2. if tax_id is null and age>=16
   
   1. search fields: first_name, last_name, birth_date
   2. additional fields: tax_id, second_name,  birthphone_certificate, phone_number
3. if age<16
   
   1. search fields: birth_certificate, birth_date
   2. additional fields: tax_id,   first_name, last_name, second_name, birth_certificate, phone_number

Return empty array if no data found

...