* lisp/image-mode.el: Use one timer and lock for slow remote calls (bug#45256)

* lisp/image-mode.el: Use one timer and lock for slow remote calls (bug#45256)

* lisp/image-mode.el (image-auto-resize-timer): New variable.
(image--window-state-change): Cancel previous timer and
remember new timer in image-auto-resize-timer.
(image--window-state-change): New variable.
(image-fit-to-window): When image-fit-to-window-lock is nil,
call image-toggle-display-image ignoring 'remote-file-error'.