The `BitAppShell` needs a new feature to automatically scroll to top on navigation

[msynk]

The BitAppShell needs a new feature to automatically scroll to the top on page navigation:

currently as discussed in the following issues the enhanced navigation (which apparently is enabled by default in Blazor WASM) causes the scroll behavior to be very undesirable in most situations:

dotnet/aspnetcore#51338

dotnet/aspnetcore#51646