This PR adds a new potentially backwards-incompatible update: for columns that are the return values of JSON functions, it'llJSON.parse() the text value and return list objects instead of serialized JSON text.

When using SQLite's builtin JSON functions, SQLite will give JSON values a special "subtype" value. We can use this "JSON subtype" to detect if a value is valid JSON. If so, we can parse the text string before returning the values back to the user.

An example:

const [list] = db
  .prepare("SELECT json_array(1, 2, 3) as list")
  .value<[number[]]>()!;
// list = [ 1, 2, 3 ]

const [object] = db
  .prepare("SELECT json_object('name', 'Peter') as object")
  .value<[{ name: string }]>()!;

// object = { name: "Peter" }

This also works for all the other JSON builtin functions, including json(), json_each(), json_tree(), and more. Other SQLite extensions can also use the JSON subtype convention in their own custom functions.

Potentially backwards incompatible

Before, these functions would just return a string, and users would probably JSON.parse() it themselves. But now, it can possibly return arrays, objects, decoded JSON strings and numbers, etc. Because of that, I think merging this PR as-is would be a major version bump (well, minor since it's pre-v1)

However, we could also add a new database-level setting to make this new behavior opt-in. Maybe something like db.enableJsonDeserializing(true) or something in the constructor. Happy to include if you think it's best!