Add support for exploded query params

[Ivan-Roger]

This allows for free-form query params in the case where they cannot be described in the openapi docs.
They will be stored as a map of strings (keys) to list of strings (values).

Example:

URI: /search?name=foo&status=active

{
    "/search": {
        "get": {
            "summary": "Search items",
            "description": "Search items",
            "operationId": "search",
            "parameters": [
                {
                    "explode": true,
                    "in": "query",
                    "name": "filters",
                    "schema": {
                        "additionalProperties": {
                            "items": {
                                "type": "string"
                            },
                            "type": [
                                "array",
                                "null"
                            ]
                        },
                        "type": "object"
                    }
                }
            ]
        }
    }
}

[wolveix]

Hey @Ivan-Roger, could you give an example of what issue this is resolving? A complete code sample always helps cut down on the time necessary to review PRs :)

[Ivan-Roger]

Hey,
Sorry. I openned the PR in a hurry. I added a description.
I'm available if you need any clarifications