Description of problem:

On a hub cluster managing ~3500 clusters the web UI consumes ~2G of memory and over 100% of cpu 

Version-Release number of selected component (if applicable):

2.7.0

How reproducible:

Always

Steps to Reproduce:

1. Set up hub cluster with ~3500 managed clusters
2. Load web UI dashboard, eg https://console-openshift-console.apps.bm-acm27.rdu2.scalelab.redhat.com/multicloud/infrastructure/clusters/managed
3. View memory and CPU usage on client side, eg using browser task manager. High CPU/memory occurs using either Firefox or Chrome.

Actual results:

CPU use over 100% and memory ~2G after page fully loads.

Expected results:

Significantly less cpu and memory requirements at steady state.

Additional info:

task manager screenshots attached.