Update the HTML head from your Blazor components

When you spin up a Blazor app and start navigating between pages you immediately run into an interesting problem. Although it seems to your users like they're switching between different pages on a web site, in reality they're always hitting the same page ( index.html for WASM or _Host.cshtml for Server) and Blazor is switching different content 'on' and 'off' (showing/hiding).