dotnet: consider adding support for "object" or "type" scope

e.g. detecting service classes using something like

```yaml
- type:
- extends: System.ServiceProcess.ServiceBase
- optional:
- api: OnStart
- api: OnStop
- api: OnPause
- api: OnContinue
```
doc: https://learn.microsoft.com/en-us/dotnet/api/system.serviceprocess.servicebase?view=dotnet-plat-ext-7.0

Start by tracing the existing YAML rule parsing and scope-matching path for the proposed `type` or `object` scope, then compare it with the ServiceBase example in the issue. Done means the supported scope is defined, the example rule can detect the intended service classes and methods, and coverage is validated by the project's tests.

Written by the indexing model from the issue text.