Add `execute(sql, args)`-style API

[penberg]

The current API looks as follows:

const result = await client.execute({
  sql: "SELECT * FROM users WHERE id = ?",
  args: [1],
});

but most SQLite JavaScript API use something like:

const result = await client.execute("SELECT * FROM users WHERE id = ?", [1]);

Unsurprisingly, LLMs assume the latter, which makes them get libSQL SDK usage often wrong.

Let's consider adding a execute(sql, args) style API, which is more familiar to people anyway.