Support Fontawesome kits & custom icons

[RCVarley]

Fontawesome offers custom kits which can contain custom icons.

My request is for the ability to register a custom kit as an iconSet.

Note: If this is already supported, could you please update the documentation to show how? Or tell me how to do it and I'll submit an update.

FYI, when uploading a custom duotone icon called store-group, the basic html implementation would look like this:
<i class="fa-kit-duotone fa-store-group"></i>.

I don't know if anything needs to happen for QIcon to handle the fa-kit-duotone class.

[ajmas]

Maybe start with the following page (it already covers some customisation info), and see if it helps:

https://quasar.dev/vue-components/icon