feat(git): save git config when creating stack (#5048)

* feat(git): save git config when creating stack

* chore(fs): test fileExists

* fix(git): fix tests to use CloneRepository

* refactor(git): move options to new object

api/http/handler/stacks/stack_create_test.go

@@ -0,0 +1,29 @@
+package stacks
+
+import (
+	"testing"
+
+	portainer "github.com/portainer/portainer/api"
+	gittypes "github.com/portainer/portainer/api/git/types"
+	"github.com/portainer/portainer/api/http/security"
+	"github.com/portainer/portainer/api/internal/testhelpers"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_stackHandler_cloneAndSaveConfig_shouldCallGitCloneAndSaveConfigOnStack(t *testing.T) {
+	handler := NewHandler(&security.RequestBouncer{})
+	handler.GitService = testhelpers.NewGitService()
+
+	url := "url"
+	refName := "ref"
+	configPath := "path"
+	stack := &portainer.Stack{}
+	err := handler.cloneAndSaveConfig(stack, "", url, refName, configPath, false, "", "")
+	assert.NoError(t, err, "clone and save should not fail")
+
+	assert.Equal(t, gittypes.RepoConfig{
+		URL:            url,
+		ReferenceName:  refName,
+		ConfigFilePath: configPath,
+	}, *stack.GitConfig)
+}