Reverting error_df optimization to fix #101

[shinga]

Description

Removes the sequence_nbr optimization logic in writer.py

Related Issue

#101

Motivation and Context

This change reverts a change to write_error_records_final() that caused error metrics to be lower than the actual errors.

How Has This Been Tested?

Tested with Databricks runtime 14.3 LTS and Spark 3.5.0
Compared and matched stats table, error table output with actual errors for 50 row_dqs on a 500 million record dataset.
Performance was not slower than v2.1.0 for this use case.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[asingamaneni]

LGTM