[Trimming] Enable trimming and AOT analyzers

[simonrozsival]

Description of Change

This PR enables trimming, AOT, and single file analyzers to assemblies where it doesn't require any changes. For Essentials.csproj and Compatibility.csproj I changed IsTrimmable to IsAotCompatible.

The only projects that don't have the analyzers enabled yet are:

• Controls.Core.csproj - will need addressing a few issues
• Controls.Xaml.csproj - will need addressing a few issues

I'm also skipping adding analyzers to:

• Test projects
• Compatibility projects
• ControlGallery projects
• *.Design projects (net472)
• Templates
• netstandard2.0 projects

Issues Fixed

Contributes to #18658

[jonathanpeppers]

@Eilon or someone in @dotnet/dotnet-maui-blazor-eng care to review?

This ignores a trimmer warning in WinForms/WPF BlazorWebView, but we filed an issue for the future at:

• BlazorWebView: Use AppContext.BaseDirectory instead of Environment.CurrentDirectory  #21750

[Eilon]

@Eilon or someone in @dotnet/dotnet-maui-blazor-eng care to review?

This ignores a trimmer warning in WinForms/WPF BlazorWebView, but we filed an issue for the future at:

• BlazorWebView: Use AppContext.BaseDirectory instead of Environment.CurrentDirectory  #21750

I'm reviewing. If we take the change in #21797, does this PR need to change at all? (I think the change in #21797 is good, but I want to test locally first)

[jonathanpeppers]

This PR doesn't need to change if #21797 goes in.

The warning suppressed here is around Assembly.Location that returns null in self-contained apps. But the code already does a null check.