Add extensibility to ingress parsing

### What should we add or change to make your life better?

There are a number of issues related to annotations and how that translates into route and cluster configuration.
* https://github.com/microsoft/reverse-proxy/issues/1479
* https://github.com/microsoft/reverse-proxy/issues/1828
* https://github.com/microsoft/reverse-proxy/issues/1550

There should be a more generic extension point for how annotations are converted into [route options](https://github.com/microsoft/reverse-proxy/blob/main/src/Kubernetes.Controller/Converters/YarpParser.cs#L172) and how rules are converted into [route matches](https://github.com/microsoft/reverse-proxy/blob/main/src/Kubernetes.Controller/Converters/YarpParser.cs#L97).

### Why is this important to you?

I have a number of custom annotations or transforms that I would like to attach to routes in a simplified manner. I also have some standards in how route matches are created that I would like to be able to apply automatically.