[Stack Monitoring] "View these instances" link for standalone instances doesn't update UI

[matschaffer]

Steps to reproduce:

1. Start up something that produces monitoring documents without a cluster uuid (logstash on docker-testing-cluster will do this today)
2. Pull up the cluster list
3. Click "View these instances" in the top warning section
4. Note that the screen doesn't change at all

Provide logs and/or server output (if relevant):

Describe the feature:

Seems like this link is supposed to go to the same place as the "Standalone Cluster" link in the table below. The URL updates, but the page doesn't change today.

Likely an artifact of the angular->react transition. The cluster listing page still contains a number of angular stubs. We might be able to remove those, clean things up and fix this bug all in the same PR.

Noticed while testing #120713

Note: when looking into this, please also look into #121605 in case these are the same issue, thank you!

[elasticmachine]

Pinging @elastic/infra-monitoring-ui (Team:Infra Monitoring UI)

[matschaffer]

Just my opinion, but I think we could just remove the link and say "Click Standalone Cluster in the table below"

It's a pretty rare case that we'll even have a standalone cluster and the link in the table below works fine and is pretty obvious.

[LeeDr]

Why is Enterprise Search showing up sometimes in main (8.1.0) as a Standalone cluster, and then navigating to Stack Monitoring again and it shows up as part of one elasticsearch cluster? This is breaking a test I have

[matschaffer]

@LeeDr pretty sure that's #121192