Adding support for Strapi Cloud provider

Strapi Cloud is the SaaS version of already know Strapi CMS.

The content url is the API url, plus the /uploads path, ie: https://project.cloud.strapi.com/uploads/imagename.ext

Returned json from image endpoint is:

{
  "id": 70,
  "name": "header.png",
  "alternativeText": null,
  "caption": null,
  "width": 1024,
  "height": 1024,
  "formats": {
    "thumbnail": {
      "name": "thumbnail_header.png",
      "hash": "thumbnail_header_48fc13d12f",
      "ext": ".png",
      "mime": "image/jpeg",
      "path": null,
      "width": 156,
      "height": 156,
      "size": 5.61,
      "url": "/uploads/thumbnail_header_48fc13d12f.png"
    },
    "small": {
      "name": "small_header.png",
      "hash": "small_header_48fc13d12f",
      "ext": ".png",
      "mime": "image/jpeg",
      "path": null,
      "width": 500,
      "height": 500,
      "size": 41.32,
      "url": "/uploads/small_header_48fc13d12f.png"
    },
    "medium": {
      "name": "medium_header.png",
      "hash": "medium_header_48fc13d12f",
      "ext": ".png",
      "mime": "image/jpeg",
      "path": null,
      "width": 750,
      "height": 750,
      "size": 84.01,
      "url": "/uploads/medium_header_48fc13d12f.png"
    },
    "large": {
      "name": "large_header.png",
      "hash": "large_header_48fc13d12f",
      "ext": ".png",
      "mime": "image/jpeg",
      "path": null,
      "width": 1000,
      "height": 1000,
      "size": 133.5,
      "url": "/uploads/large_header_48fc13d12f.png"
    }
  },
  "hash": "header_48fc13d12f",
  "ext": ".png",
  "mime": "image/jpeg",
  "size": 137.77,
  "url": "/uploads/header_48fc13d12f.png",
  "previewUrl": null,
  "provider": "local",
  "provider_metadata": null,
  "createdAt": "2001-01T00:16:32.392Z",
  "updatedAt": "2001-01T00:16:32.392Z",
  "folderPath": "/1"
}

Start by reading the existing image-provider integrations and the Strapi Cloud API example in this issue. Determine how the /uploads URL and returned image metadata should map to the module's provider interface. Done means Strapi Cloud image URLs resolve and the available image variants are handled consistently.