feat(sointu, vm): implement pure-Go interpreter for bytecode

The old "native" compiler bridged version is now started with cmd/sointu-nativetrack,
while the new pure-Go bytecode implemented bytecode interpreter is started with
cmd/sointu-track

Thus, you do not need any of the CMake / cgo stuff to run cmd/sointu-track

cmd/sointu-nativetrack/main.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/vsariola/sointu/oto"
+	"github.com/vsariola/sointu/tracker/gioui"
+	"github.com/vsariola/sointu/vm/compiler/bridge"
+)
+
+func main() {
+	audioContext, err := oto.NewContext()
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	defer audioContext.Close()
+	synthService := bridge.BridgeService{}
+	gioui.Main(audioContext, synthService)
+}