fix: icon size & support BackedEnum

[agencetwogether]

Because the Filament icon component generates the classes fi-icon and fi-size-{$size->value}, it's no longer necessary to use the $iconSizeClass variable in radio-deck.blade.php

Instead, you can directly pass the desired size to size attribute of the component.

<x-filament::icon :icon="$icon" :size="$iconSizeValue" @class([
    'flex-shrink-0',
    match ($color) {
        'gray' => 'fi-color-gray text-gray-600 dark:text-gray-500',
        default => 'fi-color-custom text-custom-600 dark:text-custom-500',
    },
]) @style([
    \Filament\Support\get_color_css_variables($color, shades: [600, 500]) => $color !== 'gray',
]) />

Indeed, without this fix, if the size 2xl was defined, the component's generated class remained fi-size-md and not fi-size-2xl. And so the icon wasn't the right size.

And with the Filament CSS icon class definitions, the sizes are correctly defined.

See filament/packages/support/resources/css/components/icon.cssfile.

Furthermore, this pull request allows the use of icons with backed enums.

The readme file has been updated accordingly.
Thanks