Add empty (no sample content) option for Blazor Hybrid

[Eilon]

Also removed unneeded favicon.

The option is available via command line by running dotnet new maui-blazor --Empty, or in Visual Studio:

To see the effect of the new option, check out this PR diff comparing the default option (with sample content) to the empty option (no sample content): https://github.com/Eilon/MauiBlazorHybridEmpty/pull/1/files

The change is based on what the Blazor Web template does, and what was already replicated in the .NET 9 MAUI Blazor + Web App template (which already has the Empty option).

Fixes #9126, #16542

[Eilon]

@javiercn / @MackinnonBuck / @SteveSandersonMS - could I please get a Blazor code review for this change?

[javiercn]

Only have 1 comment.

Does the template match the option on the web template? Doesn't the checkbox on the web template say something like "Include Sample content"?

[Eilon]

Only have 1 comment.

Does the template match the option on the web template? Doesn't the checkbox on the web template say something like "Include Sample content"?

It's an exact copy of the text and UI:

[Eilon]

And perhaps to clarify... or make things more confusing... the UI option in VS is Include sample pages, but from the command line and in the template authoring there is both that option, but also a --Empty option, which is a separate option, but easier to use from command line (I guess). Those two options together are used to compute whether sample content should be generated.

Here's the rough logic from the template.json:

      "IncludeSampleContent": { // this is the UI option in VS (also available in command line)
        "defaultValue": "true",
        "displayName": "_Include sample pages",
      },
      "Empty": { // this UI option is command-line only
        "defaultValue": "false",
      },
      "SampleContent": { // this is the computed value that uses the two previous options to decide what should be generated
        "type": "computed",
        "value": "(IncludeSampleContent) || (!Empty)"
      }

[Eilon]

@mattleibow / @Redth / @rmarinho - can I get a MAUI review so that this can get merged? It's been Blazor-approved.