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

[Juri Linkov]

>> * lisp/net/webjump.el (webjump-default-search-engine): Add user option
>> (webjump-choose-search-engine): Add function
>
> I think putting this shared functionality in the webjump package isn't
> optimal.  Webjump is "webjump.el --- programmable Web hotlist", and this
> doesn't seem related.  
>
> browse-url (or even url-something) would be more natural, I think.

webjump.el contains a list of search engines,
browse-url.el contains a list or web browsers.