message: Add "delete last frame" command
diff: @@ -171,6 +171,8 @@ export class Terminal implements Tab, Disposable {
  static registerCommands(extensionManager: ExtensionManager): void {
  const commands = extensionManager.getExtensionContextByName("internal-commands").commands;
  + commands.registerCommand("extraterm:terminal.deleteLastFrame",
  + () => extensionManager.getActiveTerminal().commandDeleteLastFrame());
  commands.registerCommand("extraterm:terminal.scrollPageDown",
  () => extensionManager.getActiveTerminal().scrollPageDown());
  commands.registerCommand("extraterm:terminal.scrollPageUp",
  @@ -772,6 +774,16 @@ export class Terminal implements Tab, Disposable {
  clipboard.setText(text);
  }
  + commandDeleteLastFrame(): void {
  + for (let i = this.#blockFrames.length-1; i >= 0 ; i--) {
  + const bf = this.#blockFrames[i];
  + if (bf instanceof DecoratedFrame) {
  + this.deleteFrame(bf);
  + return;
  + }
  + }
  + }
  +
  commandGoToNextFrame(): void {
  const viewportTop = this.#verticalScrollBar.value();
  for (const bf of this.#blockFrames) {
  