Include CIDs in JSON

[livid]

https://github.com/Planetable/Planet/releases/tag/insider-20230425-3

Example:

https://olivida.eth.limo/planet.json

[livid]

cc @mejango

Attachment CIDs are now included in JSONs. After you CMD+r rebuild, you will get a dict like this in JSONs:

      "attachments": [
        "writer-date-picker.png",
        "insider-and-debug.png",
        "stars.png",
        "planet-api-server.png",
        "social.png",
        "juicebox.png"
      ],
      "cids": {
        "insider-and-debug.png": "bafybeih5rmzaquwq4rwm7jjdtjradu62xhct67a33j4tl4evnod2cbujjm",
        "juicebox.png": "bafkreiczuqfjw5tvlq7yllzffiqq2pzv4pd7olt7wmpexrq3fdh5n3eo64",
        "planet-api-server.png": "bafybeif67ft6h5d6wbgrtxp5fzavehktgreavj44fgbqa2qds6fer4ypvy",
        "social.png": "bafkreih52l3azwncogjy4fx6atgd2xo3gdsgmvfv3cyslnua22obpnyury",
        "stars.png": "bafybeigirafgpwltarcpa4ktttreeomsr4povgyeq2e5mip5nvs6eegree",
        "writer-date-picker.png": "bafybeia7pmjbmvk6lz725h4srdmzluxtgggztxkfbia5xlsl5tzfwm44zu"
      }

You can see a live example here:

https://olivida.eth.limo/planet.json