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

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Cc: Philip Kaludercic <philipk@posteo.net>,  larsi@gnus.org,
>   52973@debbugs.gnu.org
> Date: Sat, 08 Jan 2022 20:30:06 +0200
> 
> None of the proposed functions is specific to a mode.

The way I see it, the functions in man.el are for Man-mode, and those
in hi-lock.el are for hi-lock-mode.

> When the global value of context-menu-functions
> contains one of the proposed functions, right-clicking anywhere
> will autoload every package where such context functions are defined.

This is over-engineered, IMO.  There should be no need for such
complexity.