Export the return type of syncShapeToTable so that it can be used outside lib

[samwillis]

[thruflo]

Also it would be helpful to include the stream in the return value. This is to allow components to match on it. I've recently added this to the useShape React hook as per:

const { data, stream } = useShape({...})

It would be nice to be able to access the same thing from syncShapeToTable, i.e.:

const { stream } = await pglite.electric.syncShapeToTable({
  shape: {...},
  ...
})

[yacineb]

Closed by #452