fix(core): handle escaped quotes in CSV parser

[AnanthuNarashimman]

Description

This PR fixes a critical bug in the custom parseCSVLine logic where double quotes appearing inside a quoted field (escaped as "") were incorrectly interpreted as the end of the field.

The Bug:
Previously, the parser simply toggled the inQuotes state whenever it encountered a quote. This caused inputs like "foo""bar" to be parsed as ['foobar'] instead of ['foo"bar'], resulting in silent data corruption.

The Fix:
I have updated the parseCSVLine function to include a look-ahead check. Now, when a quote character is encountered inside a quoted field:

1. It checks if the next character is also a quote.
2. If yes, it treats the pair as a single literal escaped quote (") and skips the next character.
3. If no, it functions as a standard field boundary.

Linked Issue

Fixes #23

Type of Change

• 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 not work as expected)
• Documentation update

How Has This Been Tested?

I have added a new test suite in packages/core/src/tools/read-data-file.test.ts to verify the fix and prevent regressions.

Test Coverage:

• Standard CSV: Verified simple comma-separated values.
• Escaped Quotes: Verified inputs like "He said ""Hello""" parse correctly as He said "Hello".
• Edge Cases: Verified empty fields, empty files, and lines with only headers.
• Integration: Ran npm run test and confirmed all 13 new test cases pass.

Checklist

• My code follows the code style of this project.
• I have performed a self-review of my own code.
• I have added tests that prove my fix is effective.
• New unit tests pass locally with my changes