Enhanced file reader script to allow conversion to best datatypes pos…

[kaushik-sb]

[FEATURE] Enhance CSVFileReader to support dtype conversion with null values

Description

This PR enhances the CSV file reading functionality to handle datatype conversion more robustly when null values are present.
Previously, datasets containing null values could lead to inconsistent or suboptimal datatype inference. This change ensures that when convert_dtypes is enabled in the source configuration, the dataframe uses pandas' built-in convert_dtypes() for safer and more accurate type inference.

Changes Made

• Added conditional dtype conversion in CSVFileReader:

  • If convert_dtypes is set to true in the sources of config yml, the dataframe now calls:

    result = result.convert_dtypes()

• This allows:

  • Better handling of nullable integer and string types

  • Improved consistency when null values are present in input CSV files

Definition of Done

Before submitting this pull request, please ensure that the following criteria have been met:

• All automated tests have passed successfully.
• All manual tests have passed successfully.
• Code has been reviewed by at least one other team member.
• Code has been properly documented and commented as needed.
• All new and existing code adheres to our project's coding standards.
• All dependencies have been added or removed from the project's README or other documentation as needed.
• Any relevant documentation or help files have been updated to reflect the changes made in this pull request.
• Any necessary database migrations have been run.
• Any relevant UI changes have been reviewed and approved by the UI/UX team.

##Test Evidence
CSV file processed without convert_dtypes flag in file source (Has .0 issue in numerical columns that have null entries)
test_without_convert.csv

CSV file processed with convert_dtypes flag in file source (Has correct data formatting even though columns have null entries)
test_with_convert.csv

Additional Notes

[Add any additional notes or context for the reviewer or future maintainers of this code.]

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