Empty Settings data unserialize issues with migrated content

Problem/Motivation

When showing content with a FontAwesome field that doesn't contain settings data, the unserialize fails in the FontAwesomeIconFormatter.

Steps to reproduce

I have migrated content into a content type that doesn't have any data for this field. Because of that, the unserialize of the settings data returns false, which leads to an array_filter not being able to operate on boolean `false`.

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes