lightning: support importing CSV files that contain bool type and value like true/false

## Enhancement
We imported csv files which contain bool type fields and values like true/false to TIDB table，the import task finished successfully ，but the values inserted into TiDB table are wrong.
tidb table ddl:

csv file:

tidb table:

Maybe we should transform the data type in csv files or check the data and show warnings or errors before importing instead of inserting wrong values.