Add C# API for speech enhancement GTCRN models (#1990)

dotnet-examples/speech-enhancement-gtcrn/run.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -ex
+
+if [ ! -f ./gtcrn_simple.onnx ]; then
+  curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/speech-enhancement-models/gtcrn_simple.onnx
+fi
+
+if [ ! -f ./inp_16k.wav ]; then
+  curl -SL -O https://github.com/k2-fsa/sherpa-onnx/releases/download/speech-enhancement-models/inp_16k.wav
+fi
+
+dotnet run