Create automated tests for field/widget/formatters

Problem/Motivation

The value 0 is a valid non-empty value for the social media share field 🐛 The value 0 is a valid non-empty value for the social media share field Postponed describes a problem that needs logical changes to how the field type and formatter plugins work. In order to make functional changes like this, we first need automated test coverage.

Proposed resolution

Create field type / widget / formatter test cases so that we can be sure that nothing breaks moving forward.

Remaining tasks

1. Describe what the test cases need to accomplish
2. Write test cases
3. Review; merge; and profit!

User interface changes

None

API changes

None

Data model changes

None