Blazor Hybrid (MAUI) page-component navigation

[guardrex]

Fixes #25872

Thanks @Christoph1972! 🚀 ... Sorry for the delay. We had a busy .NET 7 release cycle for docs late last year. I'm just now wrapping up last year's lower-priority issues ⛰️⛏️😅.

Internal Review Topic

David ...

• I blatantly stole 🚓👮 some of your language from the issue 😄. Thanks for those remarks.
• Thanks again for the MainPage tip. I felt there was one silly thing 😈 that I was doing wrong. I've placed that change here to head off anyone else from missing it. It also plays into my fully-working, cut-'n-paste examples effort across the Blazor docs node. Since I started providing these a few years ago, the number of docs issues has dropped dramatically.
• I've made the example generic for modal or modeless nav. It starts modeless in the example and mentions the changes to make it modal at the end.
• Check my naming because I'm not familiar with .NET MAUI conventions. For example, would it be typical to place content pages for a hybrid-type app in a "Views" folder? Did I name elements/controls/methods well?
• Are there any version deltas between .NET 6 and .NET 7 for this content? Currently, this is versioned for >= 6.0.

WRT similar content for WPF and WinForms, I'm going to hold off on that for now. I'll ask Dan and Artak about that offline later today. If they want that coverage, I'll open a new issue for it.

[davidbritch]

Approved so that you're unblocked, but with comments.

[davidbritch]

• Are there any version deltas between .NET 6 and .NET 7 for this content? Currently, this is versioned for >= 6.0.

It's all good (no version deltas).