feat: csv loader

[cachho]

Description

Adds support for csv files.

• local and remote files
• detect delimiter
• added tests

Each row is interpreted as a separate document, and stored as a comma separated string, where each row is prefixed with the header.

Name	Age	Occupation
Alice	28	Engineer
Bob	35	Doctor
Charlie	22	Student

Turns into

[
    {
        "content": "Name: Alice, Age: 28, Occupation: Engineer",
        "meta_data": {
            "url": "test.csv",
            "row": 1
        }
    },
    {
        "content": "Name: Bob, Age: 35, Occupation: Doctor",
        "meta_data": {
            "url": "test.csv",
            "row": 2
        }
    },
    {
        "content": "Name: Charlie, Age: 22, Occupation: Student",
        "meta_data": {
            "url": "test.csv",
            "row": 3
        }
    }
]

Fixes #87

Type of change

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• New feature (non-breaking change which adds functionality)
• Documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

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• Unit Test
• Test Script (please provide)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

Maintainer Checklist

• closes #xxxx (Replace xxxx with the GitHub issue number)
• Made sure Checks passed