bug#43218: EWW handles default answer incorrectly when changing a select

[Nicolas Graner <nicolas.graner@universite-paris-saclay.fr>]

Lars Ingebrigtsen <larsi@gnus.org wrote on 06/09/2020 at 13h48 :
> I think the select thing in eww has to be rewritten to allow the choices
> in a totally different way (and that should also help with <select
> multiple>, probably).

I agree. IMHO options should be presented like a list of checkboxes in a
dedicated temporary buffer. In addition to multiple selections,
advantages include:

* no mabiguity if several options have same value and/or text
* can handle option with empty text
* can handle disabled options
* present options in the order intended, not alphabetized as in minibuffer completions
* search commands are available (userful if there are many options)

Couldn't a large part of the code for checkboxes/radio buttons be reused?

Nicolas