Better handle missing outputfileSuffixes

[bmuenzenmeyer]

I am using Pattern Lab Node v2.4.1 on all platforms.

Expected Behavior

• Missing outputFileSuffixes in the config should be defaulted.

Actual Behavior

• Missing outputFileSixes cause errors

I had thought this code would suffice but it is only a local fix and did not apply to the 2.4.1 additional use.

This issue only occurs if people do not also update their edition when upgrading.
Will add a warning to that effect.