updates vulnerable depencencies, removes some warnigs from CI/CD build

[PTKu]

This pull request includes several changes to update package references, modify build settings, and clean up attributes in generated POCO files. The most important changes are grouped below by theme.

Package Updates:

• Added multiple package references in Directory.Packages.props and various .csproj files to include System.Net.Http, System.Text.Encodings.Web, and System.Text.RegularExpressions. [1] [2] [3] [4] [5] [6] [7] [8] [9]

Build Configuration:

• Added a new NuGet.config file to configure package sources and package source mapping.
• Updated ProvisionTask in cake/Program.cs to add a list of warnings to ignore in DotNetBuildSettings.

Code Cleanup:

• Removed various attributes such as [ReadOnce()], [ReadOnly()], [Container], [Group], and [RenderIgnore()] from generated POCO files to simplify the code. [1] [2] [3] [4] [5] [6]