Replace svelte-awesome with iconify

[AlexRMU]

Replace svelte-awesome with iconify (explore) through unplugin-icons.
This will provide a wider selection of icons and make them easier to use.

[josdejong]

Thanks for your suggestion. At this point, svelte-awesome works just fine, so I don't see a reason to switch right now, but let's keep it in mind when we need it in the future.