Support Fontawesome 5

Problem/Motivation

Fontawesome iconpicker has no support for Fontawesome 5 icons yet.

Fontawesome 5 was a big release and this module requires few changes to support it.

Proposed resolution

Fontawesome 5 adds support for SVGs (with JS) which is a recommended way to use fontawesome icons now.

• Discuss whether the module should stick with web fonts, upgrade to SVGs or try to support both approaches.
• Discuss backwards compatibility with Fontawesome 4 icons (https://fontawesome.com/how-to-use/upgrading-from-4)

Remaining tasks

• Update composer.json
• Update fontawesome_iconpicker.libraries.yml

User interface changes

API changes

Data model changes