Insert fake todo entry for a conflicting commit that is being applied

When stopping in a rebase because of a conflict, it is nice to see the commit
that git is trying to apply. Create a fake todo entry labelled "conflict" for
this, and show the "<-- YOU ARE HERE ---" string for that one (in red) instead
of for the real current head.

pkg/integration/tests/interactive_rebase/edit_the_confl_commit.go

@@ -0,0 +1,47 @@
+package interactive_rebase
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var EditTheConflCommit = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Swap two commits, causing a conflict; then try to interact with the 'confl' commit, which results in an error.",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.CreateFileAndAdd("myfile", "one")
+		shell.Commit("commit one")
+		shell.UpdateFileAndAdd("myfile", "two")
+		shell.Commit("commit two")
+		shell.UpdateFileAndAdd("myfile", "three")
+		shell.Commit("commit three")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Commits().
+			Focus().
+			Lines(
+				Contains("commit three").IsSelected(),
+				Contains("commit two"),
+				Contains("commit one"),
+			).
+			Press(keys.Commits.MoveDownCommit).
+			Tap(func() {
+				t.Common().AcknowledgeConflicts()
+			}).
+			Focus().
+			Lines(
+				Contains("pick").Contains("commit two"),
+				Contains("conflict").Contains("<-- YOU ARE HERE --- commit three"),
+				Contains("commit one"),
+			).
+			NavigateToLine(Contains("<-- YOU ARE HERE --- commit three")).
+			Press(keys.Commits.RenameCommit)
+
+		t.ExpectPopup().Alert().
+			Title(Equals("Error")).
+			Content(Contains("Changing this kind of rebase todo entry is not allowed")).
+			Confirm()
+	},
+})