bug#43322: Confusing menu entry for cua-mode

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Fri, 23 Oct 2020 21:17:42 +0000
> Cc: 43322@debbugs.gnu.org
> 
> We should probably replace "Shift movement mark region" with something
> else.  But it's not clear to me how to best describe it; its other
> features don't really lend themselves to a short one line description.
> 
> I see two options:
> 
> 1. Change "Shift movement mark region" to "CUA Mode (without
>    C-x/C-c/C-v)" with tooltip "Enable CUA Mode without setting
>    C-x/C-c/C-v keys".  Perhaps we could even add on to the tooltip the
>    explanatory text " (`cua-enable-cua-keys' is non-nil)".
> 
> 2. If we can make the assumption that a user who has set
>    `cua-enable-cua-keys' at least vaguely knows what they are doing,
>    perhaps we could get away with just not doing anything special in
>    that case.  In that case, we can get rid of the special handling and
>    just show the default menu entry under all circumstances.
> 
> WDYT?  Any other ideas?

I think we should do 1, but how do we name that item? what does CUA
mode do nowadays when CUA keys are disabled?