Move NewDummyCommon to pkg/common

It's too special for a utils package, and it als makes sense to put it right
next to the thing that it is a dummy for.

pkg/common/dummies.go

@@ -0,0 +1,33 @@
+package common
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	"github.com/jesseduffield/lazygit/pkg/i18n"
+	"github.com/jesseduffield/lazygit/pkg/utils"
+	"github.com/spf13/afero"
+)
+
+func NewDummyCommon() *Common {
+	tr := i18n.EnglishTranslationSet()
+	cmn := &Common{
+		Log: utils.NewDummyLog(),
+		Tr:  tr,
+		Fs:  afero.NewOsFs(),
+	}
+	cmn.SetUserConfig(config.GetDefaultConfig())
+	return cmn
+}
+
+func NewDummyCommonWithUserConfigAndAppState(userConfig *config.UserConfig, appState *config.AppState) *Common {
+	tr := i18n.EnglishTranslationSet()
+	cmn := &Common{
+		Log:      utils.NewDummyLog(),
+		Tr:       tr,
+		AppState: appState,
+		// TODO: remove dependency on actual filesystem in tests and switch to using
+		// in-memory for everything
+		Fs: afero.NewOsFs(),
+	}
+	cmn.SetUserConfig(userConfig)
+	return cmn
+}