feat: alert users to cluster disconnection and reconnect

[TristanHoladay]

Description

Adds a cluster connection check endpoint to the backend to poll for cluster connection. Upon cluster disconnection, the frontend will be notified and pop up an alert in the user's view to let them know. The backend will trigger a reconnection handler, which will infinitely retry to connect every 5 seconds until successful or user stops the app. When a new connection is made, the old cache informers will be stopped and a new cache will be created.

To Test

1. run frontend and backend, with our without auth
2. in separate terminal, cd into runtime repo and run uds run test:k3d
3. watch the frontend for alerts

Related Issue

Resolves #10

[decleaver]

Comments addressed and issue being created to look into the timing and number of network calls to /health

[TristanHoladay]

for multiple health calls #299

for automatic "reload" for user #300

[decleaver]

🚀