Add test that demonstrates bug with deleting remote branch with different name

It's maybe not very common, but it's totally possible for a remote branch to
have a different name than the local branch. This test shows that we don't
support this properly when deleting the remote branch.

pkg/integration/tests/branch/delete_remote_branch_with_different_name.go

@@ -0,0 +1,56 @@
+package branch
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var DeleteRemoteBranchWithDifferentName = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Delete a remote branch that has a different name than the local branch",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig: func(config *config.AppConfig) {
+	},
+	SetupRepo: func(shell *Shell) {
+		shell.EmptyCommit("one")
+		shell.CloneIntoRemote("origin")
+		shell.NewBranch("mybranch-local")
+		shell.PushBranchAndSetUpstream("origin", "mybranch-local:mybranch-remote")
+		shell.Checkout("master")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Branches().
+			Focus().
+			Lines(
+				Contains("master").IsSelected(),
+				Contains("mybranch-local ✓"),
+			).
+			SelectNextItem().
+			Press(keys.Universal.Remove).
+			Tap(func() {
+				t.ExpectPopup().
+					Menu().
+					Title(Equals("Delete branch 'mybranch-local'?")).
+					Select(Contains("Delete remote branch")).
+					Confirm()
+			}).
+			Tap(func() {
+				t.ExpectPopup().
+					Confirmation().
+					/* EXPECTED:
+					Title(Equals("Delete branch 'mybranch-remote'?")).
+					Content(Equals("Are you sure you want to delete the remote branch 'mybranch-remote' from 'origin'?")).
+					ACTUAL: */
+					Title(Equals("Delete branch 'mybranch-local'?")).
+					Content(Equals("Are you sure you want to delete the remote branch 'mybranch-local' from 'origin'?")).
+					Confirm()
+			}).
+			Lines(
+				Contains("master"),
+				/* EXPECTED:
+				Contains("mybranch-local (upstream gone)").IsSelected(),
+				ACTUAL: */
+				Contains("mybranch-local ✓").IsSelected(),
+			)
+	},
+})

pkg/integration/tests/test_list.go

@@ -43,6 +43,7 @@ var tests = []*components.IntegrationTest{
 	branch.CreateTag,
 	branch.Delete,
 	branch.DeleteRemoteBranchWithCredentialPrompt,
+	branch.DeleteRemoteBranchWithDifferentName,
 	branch.DetachedHead,
 	branch.NewBranchAutostash,
 	branch.NewBranchFromRemoteTrackingDifferentName,