Support request body and multiple media types under the same status code

[iongion]

Checklist:

• Run pytest tests and no failed.
• Run ruff check flask_openapi3 tests examples and no failed.
• Run mypy flask_openapi3 and no failed.
• Run mkdocs serve and no failed.

Goals:

• This allows specifying requestBody in endpoints for such cases when the api supports multiple input/output formats
• This also adds the functionality in the other PR Support multiple media types under the same status code #207
• It also attempts to address Add support for multiple custom JSON content types in the request body #100

@api.post(
    "/inference",
    request_body={
        "content": {
            # Content type
            "application/json": SAM2InferenceInput,
            "application/bson": SAM2InferenceInput,
        },
        "required": True,
    },
    responses={
        HTTPStatus.OK: {
            "description": "Inference output",
            "content": {
                # Content type
                "application/json": SAM2InferenceOutput,
                "application/bson": SAM2InferenceOutput,
            },
        },
    },
)
@tracer.capture_method
def create_sam2_inference(body: SAM2InferenceInput):
    """Perform inference with SAM2 model.

    Perform inference with SAM2 model using the given input.
    """
    output = perform_sam2_inference(body)
    return respond(output)

And also brings support for the swagger docs