Format single item arrays as an array

[fflaten]

PR Summary

Single item arrays are currently printed as single item without type-specific formatting because Is-Value expands them. Arrays with a single string or bool (more types?) will not be properly formatted.

# Current
> Format-Nicely @('a')
a

# After
> Format-Nicely @('a')                
@('a')

Related #2329

PR Checklist

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• [x] Summary describes changes
• [ ] PR is ready to be merged
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• [x] Tests are added/update (if required)
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[fflaten]

Submitting as a draft because I'm not sure if this might format items in an unexpected array somewhere because Pester wraps input internally. ~The broken test is fixed by #2329~

Alternative: Do extra checks inside if(Is-Value ...) { } to call Format-Bool, Format-String etc.

Thoughts @nohwnd ?

[nohwnd]

I will have a look will need to touch the formatting code for assert as well.