Validate received values in widgets to avoid crashes

**Describe the bug**

Some widgets throw when they receive an unexpected value, which causes the entire editor to error out.

**To Reproduce**

- Create a raw content file to edit in the CMS
- In the file frontmatter (or in the general file if it's a data file) include a property with a string value
- Configure the CMS to edit this property with a list widget
- Load the entry

**Expected behavior**

The CMS shouldn't crash.

**Additional context**

Related to #3509

This strategy should apply to both widget control components and preview components.