Keep Blazor Hybrid templates in sync with Blazor & MAUI

[BethMassi]

There are two Blazor Hybrid templates maui-blazor and maui-blazor-web. We need a way to coordinate any changes in MAUI templates that apply to hybrid apps (i.e. MainPage [done], Shell [maybe]) as well as any Blazor template updates that apply (i.e. update Bootstrap version).

[mattleibow]

The contents and some of the options should now match with #31721