Fix displayName usage in templates

[D4N14L]

Usage of the displayName field was changed in Jest 24.x (see: displayName) to always return an object of the format:

{
    color: "...",
    name: "..."
}

The current implementation leads to the displayName template printing as [object Object] instead of the actual displayName value. This change fixes this by switching usage based on the property type.

[D4N14L]

cc @palmerj3

[palmerj3]

Thank you!

[D4N14L]

@palmerj3 would it be possible to get a minor/patch version bump published? I was hoping to use this as soon as it's available :)

[palmerj3]

Yeah sorry I tried right after it was merged and github wasn't letting me create a release. I'll try again.

[palmerj3]

@D4N14L ok this is now published in 12.3.0