cursor-invisible-mode

[Juri Linkov]

There is cursor-intangible-mode in cursor-sensor.el, but I wonder why
it has no cursor-invisible-mode?  When implemented it could treat the
text that has the 'invisible' property by expanding when cursor moves
inside, and then contracting when it's out again like is demonstrated
in https://debbugs.gnu.org/35624#104

Another case where such mode could help that comes to mind is the
grep-find-abbreviate feature, where instead of pushing the button
to expand/contract the hidden part enabling cursor-invisible-mode
could expand/contract it when the cursor moves inside.

Maybe also cursor-invisible-mode could simplify the handling of 'open'
value of 'search-invisible' in isearch, not sure about that.