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!