Add Eclipse Dash license check for C# bindings NuGet dependencies

[patdhlk]

Brief feature description

Run Eclipse Dash License Tool on all NuGet dependencies in the iceoryx2-csharp project to verify license compliance, following the same process completed for the upstream iceoryx2 project.

Detailed information

The upstream iceoryx2 project has already had its dependencies approved through Eclipse iplab. The C# bindings introduce additional NuGet dependencies that need the same treatment.

Dependencies are checked per-project:

• src/Iceoryx2 (System.Memory, Microsoft.Extensions.Logging.Abstractions, Microsoft.Extensions.DependencyInjection.Abstractions)
• src/Iceoryx2.Reactive (System.Reactive)
• tests/Iceoryx2.Tests (Microsoft.NET.Test.Sdk, xunit, xunit.runner.visualstudio)
• examples/Logging (Microsoft.Extensions.Logging, Microsoft.Extensions.Logging.Console, Microsoft.Extensions.DependencyInjection, Serilog.Extensions.Logging, Serilog.Sinks.Console)
• examples/LoggingIntegration, ReactiveExample, ReactiveEventExample (System.Reactive)

A scripts/check-licenses.sh script will be added to automate the per-project license check, and the resulting DEPENDENCIES file will be committed to the repository root.

Use case

Eclipse Foundation compliance requires all third-party dependencies to be vetted through the Dash License Tool.

Additional context

See https://github.com/eclipse-dash/dash-licenses for the Dash License Tool and its .NET example.