fix: Add raw_response parameter support for request sending

[vblagoje]

Why:

Adds support for returning raw endpoint response data thus giving developers the option to bypass model validation if needed. Mandating model validation by default without a way to disable it limits flexibility and doesn't align with best practices in software design.

What:

• Actually implement raw_response flag in the request method.
• Implemented multiple unit tests to verify the new raw_response functionality for JSON and text content types.

How can it be used:

To retrieve unprocessed response data from a request, set the raw_response parameter to True:

result = petstore_expanded_spec.paths["/pets/{id}"].get.request(
    base_url="http://example.com",
    parameters={"id": "1"},
    raw_response=True
)

How did you test it:

Unit tests were created to assert correct behavior of the raw_response functionality, including:

• Verifying unparsed JSON response when raw_response is set to True.
• Verifying unparsed text response for similar conditions.
• Ensuring the default behavior of parsed response into models when raw_response is False.

Notes for the reviewer:

Ensure the new tests correctly distinguish between parsed and unparsed behavior of the response. Pay attention to the handling of different content types within the tests.