Build sherpa-onnx as a single shared library (#1078)

When `-D BUILD_SHARED_LIBS=ON` is passed to `cmake`, it builds a single shared library.

Specifically, 

- For C APIs, it builds `libsherpa-onnx-c-api.so`
- For Python APIs, it builds `_sherpa_onnx.cpython-xx-xx.so`
- For Kotlin and Java APIs, it builds `libsherpa-onnx-jni.so`

There is no `libsherpa-onnx-core.so` any longer.

Note it affects only shared libraries.

.github/workflows/riscv64-linux.yaml

@@ -123,8 +123,16 @@ jobs:
           ls -lh build-riscv64-linux-gnu/bin
           ls -lh build-riscv64-linux-gnu/lib
 
+          echo "---install/lib---"
+          ls -lh build-riscv64-linux-gnu/install/lib
+
+          echo "---install/bin---"
+          ls -lh build-riscv64-linux-gnu/install/bin
+
           file build-riscv64-linux-gnu/bin/sherpa-onnx
 
+          readelf -d build-riscv64-linux-gnu/bin/sherpa-onnx
+
       - name: Test sherpa-onnx
         shell: bash
         run: |