Add iconHtml to customize the icons in confirmation modal

[HichemTab-tech]

jquery-confirm version: v3.x.x

I'm submitting a ... [ ] bug report [x] feature request [ ] support request

Current behavior: among $.confirm method there is an option named icon used to define the font-awsome class for example :

$.confirm({
    icon: 'fa fa-warning',
    title: 'font-awesome'
});

Expected behavior: it would be nice if you add another option like iconHtml in case we need to build the icon our selfs or if we want to use Google Material icons.