bug#42708: Let users copy "*Char Help*" buffer

[Juri Linkov]

>> No other effect, cursor-in-echo-area was necessary when
>> 'read-char-choice' relied on 'read-key'.
>
> Seriously?  You've not only introduced a new function,
> `read-char-from-minibuffer', AND used it here and there
> (everywhere?) in place of `read-char` and `read-key`,
> but you've ALSO changed the behavior of `read-char-choice`,
> so it too no longer reads a char in the longstanding,
> useful way, which we can count to NOT use the minibuffer?

This is a false accusation.  I have NOT changed the behavior of
`read-char-choice`,