change: remove har2case, move all features to go version

hrp/internal/builtin/function.go

@@ -231,6 +231,7 @@ func Interface2Float64(i interface{}) (float64, error) {
 
 var ErrUnsupportedFileExt = fmt.Errorf("unsupported file extension")
 
+// LoadFile loads file content with file extension and assigns to structObj
 func LoadFile(path string, structObj interface{}) (err error) {
 	log.Info().Str("path", path).Msg("load file")
 	file, err := readFile(path)