fix(ext/node): implement DatabaseSync#applyChangeset()

[littledivy]

https://nodejs.org/api/sqlite.html#databaseapplychangesetchangeset-options

const sourceDb = new DatabaseSync(':memory:');
const targetDb = new DatabaseSync(':memory:');

sourceDb.exec('CREATE TABLE data(key INTEGER PRIMARY KEY, value TEXT)');
targetDb.exec('CREATE TABLE data(key INTEGER PRIMARY KEY, value TEXT)');

const session = sourceDb.createSession();

const insert = sourceDb.prepare('INSERT INTO data (key, value) VALUES (?, ?)');
insert.run(1, 'hello');
insert.run(2, 'world');

const changeset = session.changeset();
targetDb.applyChangeset(changeset);
// Now that the changeset has been applied, targetDb contains the same data as sourceDb. 

[marvinhagemeister]

LGTM