Optimize the experimental python types flag

[lpoulain]

Optimizes the experimental_python_types flag. Instead of checking the type for each row, check the type once for each fetch() call and compute a list of lambdas which are to be applied to the values from each row.

• A new RowMapperFactory class was created to wrap this behavior. The columns content from the status is analyzed and a list of lambda functions is created (one lambda per column)
• The experimental_python_types flag is now processed in the TrinoQuery class instead of the TrinoResult class