Properly assign label prop for MultiSelect ArrayField

[Parnswir]

Reasons for making this change

Fixes #2378

@epicfaace @fsteger do you think this would be an appropriate solution?

Checklist

• I'm updating documentation
  • I've checked the rendering of the Markdown text I've added
• I'm adding or updating code
  • I've added and/or updated tests
  • I've updated docs if needed
• I'm adding a new feature
  • I've updated the playground with an example use of the feature

[epicfaace]

Why set it to "name" but not "title"?

[Parnswir]

@epicfaace title is not yet defined here. In other places, it is set to const title = schema.title || name;, so if you think that would be the better solution here, I would add this line as well.

[epicfaace]

Thanks! I took another look and it's helpful to know that other LOCs in the same ArrayField.js have similar logic as const title = schema.title || name; -- this makes it easier to understand how it works in context (and it's not adding anything new, rather just adding something that was missing earlier).