[Dev][Build] .NET 9 Upgrade

[snickler]

Summary of the Pull Request

.NET 9 Upgrade. Requires at least Visual Studio 17.12 to compile.

PR Checklist

• Closes: #xxx
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• Tests: Added/updated and all pass
• Localization: All end user facing strings can be localized
• Dev docs: Added/updated
• New binaries: Added on the required places
  • JSON for signing for new binaries
  • WXS for installer for new binaries and localization folder
  • YML for CI pipeline for new test projects
  • YML for signed pipeline
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

The following changes have been made:

• Update TFMs to net9.0
• Update .NET Runtime-related NuGet packages to 9.x
• Add support to CI for manual triggered builds against agents running VS Preview
• Resolve Analyzer issues:
  • WFO1000: Property 'property' does not configure the code serialization for its property content.
• New Breaking Analyzers set to warning without error:
  • CA1859: Use concrete types when possible for improved performance
  • CA2263: Prefer generic overload when type is known
  • CA2022: Avoid inexact read with Stream.Read

Validation Steps Performed

[htcfreek]

.Net9 supports title bar customization natively. Might be interesting for Peek.

See https://learn.microsoft.com/de-de/dotnet/maui/whats-new/dotnet-9?view=net-maui-9.0#titlebar-for-windows .

[jaimecbernardo]

Sanity checked a build from Dart. All was good.
Code LGTM too!
Great work! Thanks for the contribution!