Extern: Searching for integer properties fails if floating point values are given

extern: https://gitlab.com/caosdb/caosdb-server/-/issues/147

Searching for property < 1.5 yields no results if property is integer typed and has a value of 1.

• Define desired behavior in server/backend -> don't touch QL backend
• Querying does not depend on the parsing of numbers as integer or float type.