bug#73027: Fwd: 31.0.50; tab-bar-formal-global erased global-modeline-string's mouse hover/click action menu

[Juri Linkov <juri@linkov.net>]

>> Also please eval these calls and show their return values.
>
> 1. (mu4e--modeline-string) :
>
> #(" 🌀0/0 " 1 2 (help-echo "mu4e favorite bookmark 'Unread messages':

Thanks for the reproducible test case.

The problem is that the mode-line keymap can't be used without
replacing the symbol 'mode-line' with 'tab-bar'.  This means that
this recipe doesn't work:

```elisp
(defun mu4e--modeline-string ()
  #(" 🌀0/0 "
  0 5 (help-echo "mu4e favorite bookmark"
       mouse-face mode-line-highlight
       keymap (mode-line . (keymap (mouse-1 . mu4e-jump-to-favorite)
                                   (mouse-2 . mu4e-jump-to-favorite)
                                   (mouse-3 . mu4e-jump-to-favorite))))))

(add-to-list 'global-mode-string '(:eval (mu4e--modeline-string)) t)

(defun mu4e-jump-to-favorite ()
  (interactive)
  (message "DONE"))

(setopt tab-bar-format (append tab-bar-format '(tab-bar-format-align-right
                                                tab-bar-format-global)))
(tab-bar-mode)
```

But after remapping the symbol 'mode-line' with 'tab-bar',
it works nicely:

```elisp
(defun mu4e--modeline-string ()
  #(" 🌀0/0 "
  0 5 (help-echo "mu4e favorite bookmark"
       mouse-face mode-line-highlight
       keymap (keymap (tab-bar . (keymap (mouse-1 . mu4e-jump-to-favorite)
                                         (mouse-2 . mu4e-jump-to-favorite)
                                         (mouse-3 . mu4e-jump-to-favorite)))))))
```