[Rating] Individual icons and colors instead of fixed star+heart only

[lubber-de]

Description

This PR provides the possibility to use any icon or color to be used in a rating instead of the previously hardcoded star or heart rating

Usage

The icon can be defined either as data-attribute data-icon

<div class="ui blue rating" data-icon="microphone"></div>

or as the JS parameter icon

$('.ui.rating')
    .rating({
        icon: 'woman'
    })
;   

The color can be provided as usual as a classname from the current color palette: ui green rating

Screenshot

<div class="ui yellow rating" data-rating="2"></div>
<div class="ui red rating" data-icon="heart" data-rating="2"></div>
<div class="ui orange rating" data-icon="circle" data-rating="2"></div>
<div class="ui purple rating" data-icon="hotel" data-rating="2"></div>
<div class="ui green rating" data-icon="key" data-rating="2"></div>
<div class="ui blue rating" data-icon="man" data-rating="2"></div>
<div class="ui pink rating" data-icon="woman" data-rating="2"></div>

Closes

Semantic-Org/Semantic-UI#6710
Semantic-Org/Semantic-UI#2399

[y0hami]

LGTM

[ColinFrick]

LGTM

[mrcasablr]

I'm the original reporter of the issue in semantic-ui project. I'm just thrilled beyond words on how quickly this was solved. I just wish semantic-ui-react changes to fomantic. I'm using sui-react and found out that this needed fixing in sui. I had no hope this would be addressed as the original issue was reported in 2016 in sui repo and you guys added this capability in 10 days! Amazing work!

@lubber-de @ColinFrick @hammy2899 Thank you!