Include icons provided by font-fabulous

[skateman]

@epwinchell created a custom fonticon set for our needs. As we want to support fonticons on custom buttons, we need this iconset to be included in the SUI.

You can find the repo here: https://github.com/ManageIQ/font-fabulous
There is (untested) support for npm/yarn, but we haven't pushed any versions yet.
If you need a version or some extra modifications in the package.json, let me know.

Thanks

[AllenBW]

Closed by#851 and #854