Add PrimaryKeyColumnName interface
Add TableName interface
Add PrimaryKeyValue interface
Rename GetPkId to GetPrimaryKeyValue
Rename interface methods
PrimaryKeyValueGetter and PrimaryKeyValueSetter interface
refactor for PrimaryKeyValueGetter
Add GetTableName interface
use NullInt8, NullInt16, NullInt32
Add ROADMAP
use NullInt64 directory. beccause reflect only supports for int64 setter