bug#62626: 29.0.60; describe-key errors on Edit → Paste from Kill Ring → [any item]

[Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

> Aren't those integer indices the reason why the recipe below:
>
>   emacs -Q
>   M-x context-menu-mode RET
>   Type "foobar" and kill it
>   C-h k and right click, then "Paste from Kill Menu", then select string
>   Observe the help buffer claims the key sequence was:
>     <down-mouse-3> <paste-from-menu> C-a
>                                      ^^^
> shows the bogus "C-a" at the end of the sequence?

Indeed.  We should probably use something
like (intern (format "entry-%d" i)) to avoid confusion.

`context-menu-mode` code has a few other differences with the "normal"
menu (e.g. it fails to truncate long strings, etc...), so we should
consolidate the two codes to keep the best of each.


        Stefan