Support deleting items from the custom commands history

In the custom commands panel you can now tab to the suggestions and hit 'd' to
delete items from there. Useful if you mistyped a command and don't want it to
appear in your history any more.

pkg/integration/tests/custom_commands/delete_from_history.go

@@ -0,0 +1,41 @@
+package custom_commands
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var DeleteFromHistory = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Delete an entry from the custom commands history",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupRepo:    func(shell *Shell) {},
+	SetupConfig:  func(cfg *config.AppConfig) {},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		createCustomCommand := func(command string) {
+			t.GlobalPress(keys.Universal.ExecuteCustomCommand)
+			t.ExpectPopup().Prompt().
+				Title(Equals("Custom command:")).
+				Type(command).
+				Confirm()
+		}
+
+		createCustomCommand("echo 1")
+		createCustomCommand("echo 2")
+		createCustomCommand("echo 3")
+
+		t.GlobalPress(keys.Universal.ExecuteCustomCommand)
+		t.ExpectPopup().Prompt().
+			Title(Equals("Custom command:")).
+			SuggestionLines(
+				Contains("3"),
+				Contains("2"),
+				Contains("1"),
+			).
+			DeleteSuggestion(Contains("2")).
+			SuggestionLines(
+				Contains("3"),
+				Contains("1"),
+			)
+	},
+})