fix: handle nil function with tool.Stopped in dtm start module

Signed-off-by: Daniel Hu <[email protected]>

Author: daniel-hutao

internal/pkg/start/start.go

@@ -24,7 +24,7 @@ func installToolsIfNotExist() error {
 				return err
 			}
 		}
-		if !t.Stopped() {
+		if t.Stopped != nil && !t.Stopped() {
 			if err := t.Start(); err != nil {
 				return err
 			}

internal/pkg/start/tool/tool.go

@@ -5,8 +5,10 @@ type stopedFunc func() bool
 type installFunc func() error
 type startFunc func() error
 type tool struct {
-	Name    string
-	Exists  existsFunc
+	Name   string
+	Exists existsFunc
+	// Stopped can be nil if it is not needed.
+	// if Stopped != nil -> Start can't be nil too
 	Stopped stopedFunc
 	Install installFunc
 	Start   startFunc