feat: add network error and timeout toast

[yuyongmao]

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

/kind api-change /kind ui-change /kind bug /kind cleanup /kind design /kind documentation /kind failing-test /kind feature /kind flake

Which issue(s) this PR fixes:

Fixes #43

[puncsky]

Toast is bad for experiences. Let's use a panel with CTA to refresh

something like: