kuma-ui: new build with various bugfixes and features

[bloqhead]

Summary

A brand new GUI build for the upcoming v0.3.2 release.

Full changelog

• Smoother onboarding functionality
• Better Kuma configuration handling. The API URL and environment are always checked and stored whenever the GUI is run, and then re-checked every time the browser is reloaded. This ensures that the user's Kuma environment is accurately displayed, especially for instances where they might switch from universal to Kubernetes, and vice versa
• Better overall handling in cases where the Kuma API might be completely unreachable
• Detection of offline dataplanes in the onboarding process, with a control for refreshing the list without having to reload the entire page
• Color-coded status indicators for when a dataplane is either online or offline (red for offline, green for online)
• Better dataplane detail view UI to indicate when a dataplane is offline
• Health Checks page added
• Proxy Templates page added
• Improved dataplanes overview page that shows general stats for all policies and entities
• "View Entity" feature added to all entity detail views that allows the user to copy the entity to their clipboard in YAML format
• "Last Updated" and "Last Connected" times have been simplified for at-a-glance viewing (e.g. "30 minutes ago", "15 hours ago", "5 seconds ago", etc)
• YAML entities are now converted from their JSON source and displayed on all detail pages as highlighted markup
• Improved breadcrumbs that display the current mesh and provides a hierarchy of pages and labels for clearer navigation
• Simple pagination on all data table views
• All entities listed in data tables are now grouped by name and the mesh they are associated with
• Improved 404 handling for instances where the user might be viewing an entity or dataplane that no longer exists
• Various small improvements to all data overview components
• Some small responsive and CSS tweaks for the overall framework and components
• All informational and documentation links now automatically go to the version the user is running. This ensures they are always looking at the documentation most relevant to them