transactions does not seem to work with indexeddb

[Spark0482]

Hello.

I'm trying to use alasql for our browser app.
We need to use transactions on IndexedDb. It seems that transactions are not implemented for INDEXEDDB.

Here's my code
`const queriesAttach = [
'ATTACH INDEXEDDB DATABASE ' + SCHEMA_NAME,
'USE ' + SCHEMA_NAME
];

return new Observable((subscriber) => {
  alasql.promise(queriesAttach)
    .then(() => alasql.promise('BEGIN TRANSACTION'))
    .then(() => alasql.promise(query))
    .then(() => alasql.promise('COMMIT TRANSACTION'))
    .then((res) => subscriber.next(res))
    .catch((error) => console.error(error));
});`

I get the error
l.engines[l.databases[l.useid].engineid].begin is not a function