Dashboard should report issues which happens on preLoad

[sleshchenko]

Describe the bug

Currently, when Dashboard fails to preload data (plugins/devfile/workspaces) it just silently does not show objects (samples cards, workspaces). Instead, it should show an error which informs users that requests fails due some reason.

It may overlap a bit with: [UD] Show a proper error page when Che API is not available #18092

Che version

• latest
• nightly
• other: please specify

Steps to reproduce

Expected behavior

Runtime

• kubernetes (include output of kubectl version)
• Openshift (include output of oc version)
• minikube (include output of minikube version and kubectl version)
• minishift (include output of minishift version and oc version)
• docker-desktop + K8S (include output of docker version and kubectl version)
• other: (please specify)

Screenshots

Installation method

• chectl
  • provide a full command that was used to deploy Eclipse Che (including the output)
  • provide an output of chectl version command
• OperatorHub
• I don't know

Environment

• my computer
  • Windows
  • Linux
  • macOS
• Cloud
  • Amazon
  • Azure
  • GCE
  • other (please specify)
• Dev Sandbox (workspaces.openshift.com)
• other: please specify

Eclipse Che Logs

Additional context