feat(data): add publish events over WebSocket

[zxl629]

Description of changes

Add support to publish events over WebSocket connection for Amplify events client. Customers can now perform the following operations to publish their events.

// WSS Connect 
const channel = await events.connect("test/events");

// WSS publish events
await channel.publish(
      { key: "my event content" },
      { authMode: "identityPool" }
);

// WSS publish events batch
await channel.publish([1, 2, 3], { authMode: "identityPool" });

Description of how you validated changes

• Manual testing with a sample app
• E2Es: https://github.com/aws-amplify/amplify-js/actions/runs/13510524961
• Unit test added/ passed

Checklist

• PR description included
• yarn test passes
• Unit Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[blakedunson]

should we adjust this comment?

[zxl629]

Yes, this comment has been removed.

[iartemiev]

Does this mean we'll close the WS connection if there's a publish error? If so, I don't think that's the behavior we want here. Publish errors would ideally be surfaced at the call site, similar to events.connect, e.g.

try {
  await channel.publish({ some: 'data' })
} catch (err) {
  console.log('publish error', err)
}

This way, WS publish is self contained / decoupled from channel.subscribe.

[zxl629]

We will not close the WS connection if there's a publish error. However, there was a bug in the implementation causing uncaught errors in Promise, it should surface the publish errors at the call site now.
Tested with:

const publishSingleEvent = async () => {
  try {
    await channel.publish(
      { key: "my event content" },
      { authMode: "userPool" }
    );
    console.log("Single event published via WS");
  } catch (error) {
    console.error(error);
  }
};

[stocaaro]

We discussed offline how I would expect event.connect should allow both publish and subscribe until the channel has been closed, after which neither publish nor subscribe should work. With multi-channel, there are oddities around how this works in this implementation.

This change adds publish events to websockets. There should be tests added for this on the provider tests.