Implement a full webui and update backend

[fiso64]

Create a full webui for the client. A WIP prototype is already in ./webui (uses typescript+svelte), this PR will update the backend to add support for some missing APIs and implement the production webui.

• Update the daemon to add the missing APIs. See ./webui/DAEMON-AUDIT.md
• Rewrite the webui. Wire it up to the real backend and serve it when daemon starts.
• Do another design pass

[fiso64]

After benchmarking both Blazor and Svelte on a small test app, I have decided to use Typescript+Svelte for the production webui after all. On firefox, I got up to a tenfold difference in both cold and warm load performance (which is very noticeable), and a 3-5x difference when live-updating the UI.

The cost is that it's not possible to reuse the c# live client (which is already used by the CLI) for the webui. Need to use openapi instead.