fix build_find_by_clause for bool values

[kalinon]

Checking for existing records where column type is bool if you search with criteria where the column is false it will query it as is NULL instead of is false.

criteria: {scryfall_uuid: UUID(9c198ffd-50c8-46ae-a4bd-75c9d39f40de),
 inventory_uuid: UUID(9ae21165-09d8-4a33-88ec-5dbf0b4b8f4a),
 foil: false,
 etched: false}
2021-08-31T20:04:53.403044Z  DEBUG - db: Executing query -- query: "SELECT EXISTS(SELECT 1 FROM `card_record` WHERE `card_record`.`scryfall_uuid` = ? AND `card_record`.`inventory_uuid` = ? AND `card_record`.`foil` IS NULL AND `card_record`.`etched` IS NULL)", args: ["9c198ffd-50c8-46ae-a4bd-75c9d39f40de", "9ae21165-09d8-4a33-88ec-5dbf0b4b8f4a"]
does not exist

after fix:

criteria: {scryfall_uuid: UUID(9c198ffd-50c8-46ae-a4bd-75c9d39f40de),
 inventory_uuid: UUID(9ae21165-09d8-4a33-88ec-5dbf0b4b8f4a),
 foil: false,
 etched: false}
2021-08-31T20:06:33.623789Z  DEBUG - db: Executing query -- query: "SELECT EXISTS(SELECT 1 FROM `card_record` WHERE `card_record`.`scryfall_uuid` = ? AND `card_record`.`inventory_uuid` = ? AND `card_record`.`foil` = ? AND `card_record`.`etched` = ?)", args: ["9c198ffd-50c8-46ae-a4bd-75c9d39f40de", "9ae21165-09d8-4a33-88ec-5dbf0b4b8f4a", false, false]
Exists Path of Ancestry (9c198ffd-50c8-46ae-a4bd-75c9d39f40de)