refactor(stacks): extract auto update logic [EE-4945] (#8545)

api/git/credentials.go

@@ -0,0 +1,13 @@
+package git
+
+import (
+	gittypes "github.com/portainer/portainer/api/git/types"
+)
+
+func GetCredentials(auth *gittypes.GitAuthentication) (string, string, error) {
+	if auth == nil {
+		return "", "", nil
+	}
+
+	return auth.Username, auth.Password, nil
+}