Ability to insert binary data on the CLI using JSON

[simonw]

I could solve round tripping (at least a bit) by allowing insert to be run with a flag that says "these columns are base64 encoded, store the decoded data in a BLOB".

That would solve inserting binary data using JSON too.
Originally posted by @simonw in #125 (comment)

[simonw]

I'm going to implement this as the reverse of #125 - binary columns in JSON are now output like this:

  {
    "name": "lorem.txt",
    "mode": 33188,
    "mtime": 1595805965,
    "sz": 16984,
    "data": {
      "$base64": true,
      "encoded": "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"
    }
  }
]

So the sqlite-utils insert command should learn to spot {"$base64": true...} values and base64 decode them before inserting them.

[simonw]

$ echo '[
    {
        "name": "transparent.gif",
        "content": {
            "$base64": true,
            "encoded": "R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7"
        }
    }
]' | sqlite-utils insert trans.db files - --pk=name