Add pagination to endpoints

[stellenberger]

this adds pagy gem to the mix with pagination onto the following endpoints:

v2 learning resources
v2 campaigns
v2 campaign actions
v1 articles

you can add custom page size using the page_size={your_custom} to the query params

default page size if it is not specified will be 25

metadata about next and prev urls are stored in the json object named pagination_metadata that can be found in the response

example response

{
    "data": [
        {
            "id": 1,
            "title": "rubber meets the road",
            "time": 0.1,
            "link": "http://waters.net/nathan.jacobson",
            "type": "",
            "learning_topic_id": 1,
            "created_at": "2022-08-09T08:55:51.094Z",
            "updated_at": "2022-08-09T08:55:51.094Z",
            "source": "",
            "release_date": "2022-03-19T00:00:00.000Z",
            "end_date": "2022-09-26T00:00:00.000Z",
            "causes": [
                {
                    "id": 32,
                    "image": "http://homenick-schultz.org/lilliam",
                    "icon": "http://goodwin-pfeffer.biz/krystal.corkery",
                    "name": "thought leader",
                    "description": "Vel aperiam sint quod.",
                    "joiners": 4,
                    "created_at": "2022-08-09T08:55:51.104Z",
                    "updated_at": "2022-08-09T08:55:51.104Z",
                    "joined": false
                }
            ],
            "completed": false
        },
        {
            "id": 2,
            "title": "agile marketing",
            "time": 0.1,
            "link": "http://daniel-senger.name/ginger.jakubowski",
            "type": "",
            "learning_topic_id": 2,
            "created_at": "2022-08-09T08:55:51.127Z",
            "updated_at": "2022-08-09T08:55:51.127Z",
            "source": "",
            "release_date": "2022-04-09T00:00:00.000Z",
            "end_date": "2022-11-28T00:00:00.000Z",
            "causes": [
                {
                    "id": 34,
                    "image": "http://moen.org/hal.mohr",
                    "icon": "http://bartoletti-crist.net/franklyn_green",
                    "name": "bandwidth-constrained",
                    "description": "Expedita exercitationem accusamus quia.",
                    "joiners": 83,
                    "created_at": "2022-08-09T08:55:51.133Z",
                    "updated_at": "2022-08-09T08:55:51.133Z",
                    "joined": false
                }
            ],
            "completed": false
        }
    ],
    "pagination_metadata": {
        "count": 5,
        "page": 1,
        "pages": 3,
        "next": 2,
        "prev": null,
        "next_url": "http://localhost:3000/api/v2/learning_resources?page=2&page_size=2",
        "prev_url": "http://localhost:3000/api/v2/learning_resources?page_size=2"
    }
}