Fix wrong handling of minibuffers when frames get iconified/made invisible

Fix wrong handling of minibuffers when frames get iconified/made invisible

This should fix bug #47766.

* lisp/window.el (window-deletable-p): Add a quote where it was missing from
minibuffer-follows-selected-frame.

* src/frame.c (check_minibuf_window): Delete the function.
(delete_frame): In place of calling check_minibuf_window, call
move_minibuffers_onto_frame, possibly to move minibuffers onto the new current
frame.
(Fmake_frame_invisible, Ficonify_frame): Remove calls to check_minibuf_window.

* src/minibuf.c (Factive_minibuffer_window): Search the frames for the active
minibuffer rather than just assuming minibuf_window has been correctly
updated.