Adding hub settings for Web PubSub

[vicancy]

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context. List any dependencies that are required for this change.

Fixes # (issue)

Checklist

• Is this feature complete?
  • [x] Yes. Ready to ship.
  • [ ] No. Follow-up changes expected.
• Are you including unit tests for the changes and scenario tests if relevant?
  • [x] Yes
  • [ ] No
• Did you add public API?
  • [x] Yes
    • If yes, did you have an API Review for it?
      • [ ] Yes
      • [ ] No
    • Did you add <remarks /> and <code /> elements on your triple slash comments?
      • [ ] Yes
      • [ ] No
  • [ ] No
• Does the change make any security assumptions or guarantees?
  • [ ] Yes
    • If yes, have you done a threat model and had a security review?
      • [ ] Yes
      • [ ] No
  • [x] No
• Does the change require an update in our Aspire docs?
  • [x] Yes
    • Link to aspire-docs issue:
  • [ ] No

Microsoft Reviewers: Open in CodeFlow

[davidfowl]

/azp run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[davidfowl]

I think I'd prefer to see this look more like the other resources with child resources:

var wps = builder.AddAzureWebPubSub("wps1");
var hub = builder.AddHub("chat");

var web = builder.AddProject<Projects.WebPubSubWeb>("webfrontend")
    .WithExternalHttpEndpoints()
    .WithReference(wps);

// Now only works in production since localhost is not accessible from Azure
if (builder.ExecutionContext.IsPublishMode)
{
    hub.AddEventHandler($"{web.GetEndpoint("https")}/eventhandler", systemEvents: ["connected"]);
}