Improve resources page performance with many resources

[JamesNK]

The dashboard resource's page subscribes to resource updates. Along with the subscription is a collection of initial data that were cached resources.

This didn't work quite as intended. The subscription (plus initial data) returned to the UI didn't wait for the data to be populated from the server, so it was always empty when Aspire started up or the user refreshed the browser on the resources page.

This PR updates the dashboard client to wait until initial data is populated before returning the subscription + initial data. The UI has more data to immediately render and the page finishes loading much faster.

Dashboard with 100 resources...

10+ seconds to load before (note the page scroll bar as data loads):

1-2 seconds to load after:

Microsoft Reviewers: Open in CodeFlow

[JamesNK]

A normal app like TestShop also feels faster 🚀

Before resources appear quickly over 1 second.
After resources all display immediately.

[DamianEdwards]

The "No resources found" message before any show up bothers me a bit. What do we think about changing it to something like "Waiting for resources" or similar, so it doesn't sound so final and is more inline with the real-time nature of the view?

[JamesNK]

Slow loading might be related to microsoft/fluentui-blazor#1621. This PR reduces the number of re-renders which then causes fewer Expression.Compile calls. Regardless, this is still a good change.

[JamesNK]

The "No resources found" message before any show up bothers me a bit. What do we think about changing it to something like "Waiting for resources" or similar, so it doesn't sound so final and is more inline with the real-time nature of the view?

I noticed it too #2568

[davidfowl]

@JamesNK are you going to rebase this change?

[JamesNK]

@JamesNK are you going to rebase this change?

Done

Review please 🙏