feat: Waku v2 bridge

Issue #12610

vendor/github.com/anacrolix/missinggo/path.go

@@ -0,0 +1,20 @@
+package missinggo
+
+import (
+	"os"
+	"path"
+)
+
+// Splits the pathname p into Root and Ext, such that Root+Ext==p.
+func PathSplitExt(p string) (ret struct {
+	Root, Ext string
+}) {
+	ret.Ext = path.Ext(p)
+	ret.Root = p[:len(p)-len(ret.Ext)]
+	return
+}
+
+func FilePathExists(p string) bool {
+	_, err := os.Stat(p)
+	return err == nil
+}