Improve Perceived Load Time

[richard-cox]

• When the UI loads there's a number of blocking steps
• We don't show screen content until we've navigated passed these gates
• This can result in a number of different loading indicators before the user can see screen content
• Instead we should let the user through these gates and show content careful until information from those steps are loaded
• Gates
  • Before any layout is shown - Authentication Middlware
  • Default Layout
  • all screen content - managementReady
    • Side Nav - clusterReady
    • Main Section - clusterAndRouteReady
  • Generic Lists - fetch
  • Generic Detail Components - fetch
• How we handle screen content when there's missing info is up for discussion (with UX)
  • We could show loading indicators for the specific section?
• This issue may overlap with a few others, but concentrates on avoiding blocking conditions that stops the UI from loading
  • https://github.com/rancher/dashboard/issues/6829
  • https://github.com/rancher/dashboard/issues/9304
  • https://github.com/rancher/dashboard/issues/9201

[richard-cox]

• Consider full page / partial loading indicators
• Dropdowns - fetching all up front in $fetch vs in background / only when scroll to element. Need to wire in new resource selector dropdown (server-side pagination backed)