Add CloudFront invalidation step to S3 Sync

[lkurz]

A cloudfront invalidation step may be required to clear CF cache after some syncs.
Check the default settings.
Otherwise patience required for an expiration to occur and the changes to appear.

[lkurz]

REVIEW: [AWS S3 Sync with CloudFront Cache invalidation and Google Closure Compile · Actions · GitHub Marketplace]
( https://github.com/marketplace/actions/aws-s3-sync-with-cloudfront-cache-invalidation-and-google-closure-compile)