bug#52973: Adding a few context-menu-mode commands

[Juri Linkov]

>>> > Maybe I'm missing something, but I don't see the actual integration
>>> > with context-menu-mode?
>>>
>>> Each commit adds a function that can be added to context-menu-functions.
>>
>> That was my guess, but without having those additions, not even as a
>> user option, or (better) automagically when context-menu-mode is
>> turned on, those functions are just dead ballast, aren't they?
>
> From my understanding of bug#50552, this was preferred.

bug#50552 proposed to add to every package such lines:

  (custom-add-choice 'context-menu-functions
                     '(function-item :tag "Dictionary menu" 
context-menu-dictionary))

but 'custom-add-choice' fails on the current structure of
'context-menu-functions', so either a new function 'custom-add-repeat-choice'
should be created, or better would be to improve the existing
'custom-add-choice' to handle the choices inside 'repeat'.