Blazor Web App with an API call

This sample updates the `Weather`` page in the default Blazor Web App to make an API call from the client to the server when the page is prerendered and uses the Auto render mode.

• The Weather component depends on an IWeatherService for getting the weather data. This insulates the component from needing to know where it is running.
• The server project has a WeatherService that generates the weather data and is exposed as an API endpoint.
• The client project has a WeatherService that calls the server API endpoint to get the weather data.
• The Weather page is prerendered using static streaming rendering, so the page loads immediately with a "Loading..." placeholder and then is updated with the weather data.
• The Weather page then renders using the Auto interactive render mode, so it renders initially from the server over a WebSocket while the .NET runtime is downloaded, and then switches to WebAssembly for future visits.
• The Weather page persists its prerendered state so that the state can be reused when the page renders interactively.
• Links to the Weather page disable enhanced navigation (data-enhance-nav="false"), which is currently incompatible with persisted component state (dotnet/aspnetcore#51584)